Turn off the programs that load into RAM on startup. Go Start > Run, type MSCONFIG in the "Open" field, then click on OK. Click on the Startup tab, and uncheck anything that's not essential. Do you really need "iTunes Helper"? Don't be afraid to uncheck functions, as Windows will open anything it really needs.
Optimize USB and FireWire external hard drives for performance. Go Start > Settings > Control Panel. Double-click on System, click on the Hardware tab, and click on Device Manager. Click on the + symbol next to Disk Drives, right-click on your external drive, and select Properties. Click on the Policies tab, and choose "Optimize for Performance" (Fig. 1) There is a tradeoff, though; to avoid potential data loss, use the "Safely Remove Hardware" option in the system tray (the button with the green arrow) when disconnecting the drive.
Optimize internal drives for performance. Follow the same steps as above, but right-click on an internal drive instead of an external one. Select Properties, click on the Policies tab, and choose "Enable Write Caching on the Disk."
Enabling write caching on external drives can improve performance.
Use ReadyBoost. This is the only tip that isn't free, but with Windows Vista you can insert a USB thumb drive (up to 4GB) and when you do, you'll be prompted as to whether you want to enable ReadyBoost (Fig. 2). This adds more memory to your system; it isn't the same as adding more system RAM, but is more like having a really good disk cache. The improvement in speed is noticeable for just about anything other than continuous streaming of data. You do need a fast USB drive; if it isn't fast enough, Windows Vista will notify you that it's not suitable.
ReadyBoost is a great way for Windows Vista users to speed up data transfers.
Be careful about automatic updates. Windows Automatic Update is worth leaving on, as security patches for Internet Explorer are relatively frequent. But some automatic updates essentially take over your computer while they do their job, which can interfere with your work. Most automatic updates have an option where you can ask to be notified of updates, which lets you decide whether to install them immediately or wait. Another option is to schedule updates for when you're not using your computer.
For your audio interface, use ASIO instead of MME or WDM drivers with Sony Creative Software applications. Most interfaces have drivers for all three, but MME and WDM are much slower. And never use any driver that's "emulated."
With ASIO, give priority to Background Services. Sony's programs support the low-latency ASIO protocol, but for best results, go Start > Settings > Control Panel. Double-click on System, click on the Advanced tab, and under Performance, click on Settings (Fig. 3). When the Performance Options window opens, click on the Advanced tab and for Processor Scheduling, choose "Background Services."
Giving priority to background services helps ASIO work more efficiently.
Check periodically for new drivers for hardware. New drivers often result in better performance. And don't forget your graphics card; graphics performance often affects audio.
Defragment your drives periodically. This isn't as important as it once was, but a really fragmented drive can slow things down.
Don't disable System Restore. Some people claim disabling System Restore improves performance, but it's worth taking the teeny (if any) performance hit in exchange for being able to return to a restore point when needed.