If you've worked through my article on essential Windows settings for audio production, you've already made the changes that will benefit most people most of the time. This companion piece goes a step further—into your BIOS, the Windows Registry, and some drive configuration choices that can make a meaningful difference to how your system handles realtime audio.

These tweaks require a bit more confidence than the ones in the first article. Some of them involve editing values in the Windows Registry, which is something a lot of people find intimidating. Others require you to reboot into your BIOS—the low-level firmware that controls your motherboard's hardware before Windows even loads.

None of these changes are dangerous if you follow the instructions, and I'll explain exactly what each one does and why it's safe. But if any of this feels like too much, the settings in the first article will get you most of the way there on their own.

Disable Unnecessary Startup Applications

Every application that launches when you start your PC is consuming memory and CPU time before you've even opened your DAW. Some of these are essential—your audio interface's control software, for instance. But many of them are not, and over time they accumulate as you install more software. Cloud sync clients, chat apps, update checkers, hardware RGB controllers, game launchers—all of them sitting in memory, occasionally phoning home, and collectively nibbling away at the resources your DAW needs.

Press Ctrl+Shift+Esc to open Task Manager, then click on the Startup apps tab. You'll see a list of everything that runs when Windows boots, along with an estimate of each application's impact on your startup time. Right-click anything you don't need running at all times and select Disable. If you're not sure what something is, right-click on it and you'll find a Search online option which will usually give you a pretty reliable explanation of what something does and whether or not it's useful to you.

A good rule of thumb: if it's not related to a core system function, your audio hardware, your DAW or any software you use frequently, disable it. Do you really need your printer to be listening for faxes 24/7? Unless you're running a pharmacy of a 1990s law firm on the side, probably not—disable it. Do you need your backup software to be running at all times? Well yes, you probably do—leave it enabled.

Pay particular attention to anything from hardware manufacturers. Graphics card utilities, motherboard "optimisation" tools, and peripheral software (Corsair iCUE, Razer Synapse, Logitech G Hub and so on) are often set to run at startup by default and can be significant resource hogs. If you don't need RGB lighting control or macro management while composing, turn them off.

In any event, disabling a startup entry doesn't uninstall or remove anything—it just stops the application from launching automatically. If you experience any issues, you can just reenable it again.

Disable USB Root Hub Power Management in Device Manager

In the first article I covered disabling USB selective suspend in your power plan. This is the belt-and-braces follow-up. Even with selective suspend disabled at the power plan level, individual USB devices can have their own power management overrides—and Windows doesn't always respect the global setting for every device. This is one of those maddening inconsistencies that can leave you tearing your hair out trying to diagnose an intermittent dropout.

The fix is to go through each USB controller in Device Manager and explicitly tell it not to power down. Right-click the Start button and select Device Manager (or type devmgmt.msc into the Windows search bar). Expand the section called Universal Serial Bus controllers. For every entry that says USB Root Hub, Generic USB Hub or Generic SuperSpeed USB Hub right-click it, select Properties, go to the Power Management tab, and untick Allow the computer to turn off this device to save power.

Yes, you need to do this for each one individually. It's tedious, but it only takes a couple of minutes and you only need to do it once. (Unless Windows decides to reset these settings after an update, which it occasionally does. It's worth rechecking if your USB devices start behaving strangely.)

Disable Global C-State Control in Your BIOS

This one sounds intimidating, but it's actually very straightforward—and it can make a real difference to your DPC latency.

C-States or CPU Idle States are power-saving states that your CPU cores can enter when they aren't being fully utilised. The deeper the C-State, the less power the core draws—but also the longer it takes to wake back up when it's needed. In theory, your CPU should be able to drop in and out of these states seamlessly—but in practice, the wake-up time from deeper C-States can introduce latency spikes that are long enough to disrupt realtime audio processing.

This is relevant to both AMD and Intel processors, though the specifics vary. AMD's Ryzen chips—like the ones we use for our OPUS 101 Pro Audio builds—use quite aggressive power management, while Intel's hybrid-core designs from 12th generation onwards have their own quirks with Efficiency cores entering deeper sleep states. Either way, disabling C-States is a safe and effective fix.

To disable C-States, you'll need to enter your BIOS—this is usually done by pressing Delete or F2 at the beginning of your computer's boot-up sequence. (There isn't a huge amount of time in which to press the appropriate button, so in common with most people, I usually turn on the machine and then repeatedly hit the F2 button until the BIOS comes up. If you see a swirly circle indicating that Windows is loading, you've missed your chance and you'll need to reboot again.)

The exact location of this setting varies between motherboard manufacturers, and even between different boards from the same manufacturer—so I'd recommend searching for your specific motherboard model (e.g. "ASUS TUF Gaming B650-Plus disable C-States") to find the right path through the menus. The setting you're looking for is generally under the Advanced menu, and usually called something like Global C-State Control. You want to set it to Disabled.

The only real downside to doing this is a slight increase in idle power consumption and heat, since your CPU cores will no longer enter their deepest sleep states. On a desktop workstation with decent cooling, this is completely negligible—we're talking single-digit watts. Your CPU will still boost and throttle normally; it just won't drop into the low-power modes that can cause problems for audio.

I used to think this advice was a bit old-fashioned—it was standard practice back in the Intel Core 2 Duo era, then fell out of favour for a while as Intel and AMD got better at fast wake-up times. But modern chips with their complex chiplet or hybrid-core architectures have made it relevant again. For an audio workstation, it's still one of the first things to try if your latency is misbehaving.

Keep Your BIOS Up to Date

While you're in the BIOS, it's worth checking whether you're running the latest version. Your BIOS is the low-level system your motherboard uses to run your computer, and motherboard manufacturers release updates to it fairly infrequently—but when they do, these updates can address issues with memory compatibility, USB behaviour and power management that directly affect audio performance.

Check your motherboard manufacturer's support page every few months and see if there's anything new. As a general rule, only download and install stable releases, not betas—and make sure you follow the instructions carefully, because a BIOS update is one of those things you want to get right first time. Getting it wrong may cause your PC to stop booting up altogether, although this can usually be remedied by resetting the motherboard's CMOS or using your motherboard's BIOS Flashback button. But better just to follow the BIOS installation instructions carefully!

Tweak Network Throttling and System Responsiveness in the Registry

This is one of those tweaks that sounds like it has nothing to do with audio—but it does, and the improvement can be surprisingly noticeable.

Windows has a built-in mechanism that throttles network traffic in order to give multimedia applications (like video and audio playback) more CPU time. Sounds helpful, right? The problem is that the throttling mechanism itself introduces DPC latency spikes, because it's constantly interrupting the CPU to manage the flow of network packets. Even if you're not doing anything network-intensive, this process is ticking away in the background.

This, incidentally, is why a lot of audio optimisation guides recommend disabling your network adapter entirely before a session. There's some logic to it—if you remove network traffic from the equation, the throttling mechanism has nothing to do. But in practice, disconnecting from the internet every time you want to make music is a pretty miserable workflow. Many plugins require online licence checks, you might be streaming samples from a NAS, and let's be honest—you probably want to be able to watch tutorials, read the news or just kill a bit of time doomscrolling without having to constantly plug-in and unplug your Ethernet cable. The registry tweak below addresses the actual problem rather than asking you to work around it.

To make this change, you'll need to open the Windows Registry Editor. This may sound scary, but if you haven't used it before, don't worry—it's just a database of settings that Windows uses to configure itself, presented as a tree of folders. Type "regedit" into the Start menu and run it as Administrator. You'll see a panel on the left with folders you can expand, a bit like File Explorer. Navigate through the folders to reach the following location:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile

(Click the arrow next to each folder name to expand it: HKEY_LOCAL_MACHINE, then SOFTWARE, then Microsoft, and so on until you reach SystemProfile.)

In the right-hand panel you should see a value called NetworkThrottlingIndex. Double-click it. You'll get a small dialog box with a field for Value data and a choice between Hexadecimal and Decimal. Make sure Hexadecimal is selected, then change the value to ffffffff (that's eight Fs). This effectively tells Windows to stop throttling network packets altogether.

While you're in the same location, look for a value called SystemResponsiveness—it should be right underneath the first one. Double-click it and change the value to 0 (that's a zero) with Hexadecimal selected. This determines what percentage of CPU resources Windows reserves for background tasks. The default is 20% (in hex: 14), meaning a fifth of your processing power is set aside for things like indexing, telemetry and system maintenance—even while your DAW is trying to crunch numbers in realtime. Setting it to 0 tells Windows to prioritise the foreground application. Despite what you might expect, this doesn't actually starve background processes entirely: Windows internally treats a value of 0 the same as 10%, so your antivirus, system services and other essentials will still get the CPU time they need.

Neither of these changes will cause any instability or system issues. They're both well-documented settings that Microsoft provides specifically for multimedia workloads. If you ever want to revert them, just set NetworkThrottlingIndex back to a (yes, just the letter a) and SystemResponsiveness back to **14 **(both in hexadecimal).

Disable SysMain

SysMain (formerly known as Superfetch) is a Windows service that tries to guess which applications you're likely to open next and preloads them into memory so they launch faster. It does this by analysing your usage patterns and caching data from frequently used applications in the background.

On a general-purpose PC, this is a reasonable idea and quite nifty. On an audio workstation, it's a problem, for two reasons. Firstly, SysMain competes with your DAW and sample libraries for RAM—and if you're running a large orchestral template that needs every gigabyte it can get, the last thing you want is Windows using up memory to preload (sigh) Microsoft Edge. Second, the background disk activity SysMain generates can cause latency spikes as it reads data from your storage drives, potentially interfering with your sampler's ability to stream samples smoothly.

To disable it, press Win+R to open the Run dialog, type services.msc and press Enter. This opens the Windows Services console. Scroll down to SysMain, double-click it, and change the Startup type to Disabled. Click Stop if it's currently running, then click OK.

This is completely safe. Your applications might take a fraction of a second longer to open from cold, but since you're almost certainly launching your DAW at the start of a session and leaving it open, this is irrelevant. What you gain in return is more predictable memory usage and fewer background disk operations competing with your audio workflow.

Install and Configure ISLC

ISLC (Intelligent Standby List Cleaner) is a small, free utility by Wagnardsoft that addresses two issues Windows doesn't handle well on its own.

The first is the memory standby list. Windows maintains a list of recently used data in memory that it considers low priority—it's not actively needed, but Windows keeps it around in case it's wanted again soon. The problem is that this standby list can grow very large over time, and when Windows eventually decides to flush it, the sudden burst of memory management activity can cause a noticeable stutter. ISLC periodically clears this list before it gets too bloated, keeping things smooth.

The second is the system timer resolution. Windows has an internal clock that it uses to coordinate when things happen—scheduling tasks, switching between processes, etc. By default, this clock ticks every 15.6 milliseconds, which is fine for general computing but pretty coarse for realtime audio. ISLC can increase the tick rate to every 0.5 milliseconds, giving Windows a much more precise sense of timing and helping your DAW's audio engine stay on the beat.

This tweak feels a bit counterintuitive when we've just spent half a morning deleting bloatware and software that starts up automatically. But ISLC is very lightweight, and currently the cleanest way to handle both of these issues. It's well established in both the audio and gaming communities, and it sits quietly in your system tray doing its job.

Download it from Wagnardsoft's website, unzip it to a folder somewhere sensible (C:\ISLC, for instance), and run it. Tick Start ISLC minimized and Launch ISLC on user logon so it runs automatically. Set the Wanted Timer Resolution to 0.5000 then click Start. Now you can minimise the application to the tray and never think about it again.

Set Up Windows Defender Exclusions for Your DAW and Sample Folders

Windows Defender's realtime protection scans files as they're read from and written to disk. This is sensible behaviour for a general-purpose PC, but on an audio workstation it means your antivirus is inspecting every sample your DAW streams and every audio file it records—all in realtime, all competing for the same disk and CPU resources your audio needs.

The symptoms are often subtle and hard to diagnose. You might not get obvious dropouts, but you might notice slightly higher CPU usage in your DAW than expected, or the occasional tiny hesitation when loading a new instrument. These are the kinds of micro-interruptions that Defender scanning can introduce.

Open **Windows Security > Virus & threat protection and then under Virus & threat protection settings click on Manage settings. **Then scroll down to the bottom of the page where it says Exclusions and click Add or remove exclusions. Add folder exclusions for your sample libraries, or, if your sample libraries are all neatly contained on one or two drives, add those entire drives (F:\ or J:\ or whatever). Also add your DAW project folders. Then click Add an exclusion > Process and type the filename of your DAW executable (e.g. "Cubase.exe", "REAPER.exe", "ProTools.exe").

This does not compromise your security in any meaningful way. Your sample libraries are not going to contain malware—they're audio files you've purchased from reputable developers. And your DAW's own files are being generated by software you trust. Defender will continue to scan everything else on your system normally.

(It goes without saying that if you are running a third-party antivirus these days, you should uninstall it and just use Windows Defender instead. It is the best antivirus out there, free with your operating system, very lightweight, and updated frequently.)

Disable Search Indexing on Your Sample Drives

Windows maintains a search index of your files so that searches in File Explorer return results quickly. To keep this index up to date, a service called Windows Search runs in the background, constantly scanning your drives for new or modified files. On a sample drive containing hundreds of thousands of small audio files, this indexing process can generate significant disk activity—competing with your sampler for access to the very files it's trying to stream.

You don't need your sample drives indexed. You're never going to search them from File Explorer—you find your instruments through your sampler or library manager, not by typing filenames into a search bar.

To exclude a drive from indexing, open Control Panel > Indexing Options (or just type "indexing options" into your Windows Search bar) and click Modify. Untick any drives that contain sample libraries or DAW project files, then click OK. Windows will remove those drives from its index, and the background scanning will stop.

If you want to go a step further, you can disable the Windows Search service entirely. Press Win+R, type services.msc and press Enter. Find Windows Search in the list, double-click it, set Startup type to Disabled, click Stop, then OK. This will disable search indexing across your entire system, which means File Explorer searches will be slower—but if you rarely use them, that's a trade-off worth making on an audio workstation.

A Note on Sample Drive Formatting

Finally, a little tip that may be too late for you to implement in your current setup, but might be useful for next time. If you're installing a new sample drive or reformatting an existing one, there's one setting worth changing before you start copying files across.

When Windows formats a drive, it divides the available space into small chunks called allocation units (sometimes called clusters). These are the smallest units of space the drive can assign to a file—so even a tiny file will occupy at least one full allocation unit. The default size is 4KB, which is fine for general use, but sample libraries usually consist of thousands of large audio files, and a larger allocation unit size means fewer filesystem operations per file read. That's why formatting with 64KB allocation units can noticeably improve sample loading and streaming performance.

I'm not going to walk you through how to do this because I don't want someone casually skimming this article and accidentally deleting all the data on their sample drive! I suggest searching or asking your favourite LLM. But next time you are formatting a sample drive, just remember to change the allocation unit size to 64K when the time comes.