Optimize Your Storage
If you installed Windows 7 as an upgrade from Windows Vista, you'll find a folder labeled C:\Windows.old. This folder, as you might expect, holds the full contents of your old Windows Vista system. It's huge, and it's a waste of space. Scroll through the folders for any files that you want to save in your new Windows 7 OS, and then delete the entire folder from your drive. Space saved.
If your PC has multiple hard drives, you can boost performance by moving the location of the system's paging file from the drive containing the C:\ partition to a separate hard drive. To do that, open Control Panel and choose System. From there, click Advanced System Settings. Select the Advanced tab, and then click the Settings button under the Performance category. On the new window that pops up, choose the Advanced tab. Finally, click Change. Uncheck the box labeled Automatically manage paging file size for all drives. Select C: from the Drive box and switch it to the No paging file option. Next, select a different hard drive and choose System managed size. Click OK and restart your computer.
Pushing Your Performance
To create a faster Windows 7 experience, start by modifying the amount of time that mouse-over boxes and clicked menus take to appear. Click on the Windows Start button and type regedit into the 'Search programs and files' box. Welcome to the Windows 7 Registry--don't touch or modify anything without good reason. Left-click on the expandable arrow next to HKEY_CURRENT_USER. Expand the Control Panel folder, and then click directly on Desktop in the hierarchy. In the right pane, look for and double-click MenuShowDelay. Change the value from 400 to any lesser number that's 1 or greater; this figure represents the milliseconds of delay between your click and a menu's display. Restart the computer to apply the changes immediately, or continue to the next tweak.
See the folder labeled Mouse (below Desktop)? Click that, and then search for and select the MouseHoverTime Registry key. Just as before, change this value to any lesser number that's 1 or greater. Close the Registry Editor, restart the computer, and you'll have faster mouseovers.
If you're willing to sacrifice looks for speed, you can modify the visual settings of the Windows 7 interface to emphasize performance over presentation. Go back to the System section of Control Panel and click on Advanced System Settings again. On the System Properties window that appears, choose the Advanced tab and then click on the Settings box underneath the Performance category. The Performance Options window will pop up. There, you'll see a list of checked boxes that correspond to all of the window dressing in the operating system.
If you don't mind transforming your OS into a clone of Windows 2000, click the button that tells Windows to adjust its visual settings for best performance. It's a harsh step to take, though--if you'd prefer a piecemeal approach, uncheck only the boxes that relate to Windows Aero (such as Aero peek and transparent glass). You'll retain a semblance of a pretty desktop while still improving performance a teeny bit.