Tweak Windows XP
Everyone wants their machine to run faster. Here we will cover some basic tweaks which will improve the performance of Windows XP. These tweaks are designed for Windows XP. First of all, please make sure you have at least 256 MB of RAM, 512MB is preferred(more are better).
Always keep your system up to date by using the Windows update software. If your computer hasn't installed that, you can install it from Microsoft's website at: http://windowsupdate.microsoft.com/
After the Windows update software is installed, we suggest you config it to download/install future updates automatically in the background.
You need to ensure that you have the latest versions of all your hardware drivers. The ones on the original Windows CD-ROM are usually out of date. Updated Video and SCSI/SATA drivers can significantly improve the performance of your computer.
Hard Drive Performance
If you are a SATA disk, make sure you installed the driver
for sata controller and disk driver, and also make sure to
enable the ACPI support in BIOS.
Minimize Background Applications and Services
Press CTRL-ALT-DEL while in Windows and bring up the Task Manager. Notice how many programs are running in the background. Each program steals memory and CPU cycles. To stop programs from automatically starting, use msconfig to select the programs to start, and disable un-needed programs.
Removed Unused Programs, Protocols, and Fonts
Uninstall any Programs that you do not use. Also remove any Fonts that are not used. This will free up disk space and make the machine boot faster. You should also remove any temporary files located in the C:\TEMP, c:\windows\prefetch, or C:\WINDOWS\TEMP directories. Also remove any unused Network Protocols such as NetBEUI or IPX.
Windows does not unload dll files a program has used after it has been closed, to speed up a possible restart of the program.
Use RegEdit to edit: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer Add the DWORD value named: AlwaysUnloadDLL and set it to 1
Windows uses your Hard Drive as swap memory but its default configuration can cause a major loss of performance with the memory swap file getting moved around.
Select System icon from the Control Panel - Performance and Maintenance, select Advanced Tab, select Performance areas, and click on Settings Under virtual Memory click Change. The Initial and Maximum size should be equal otherwise Windows will keep resizing the file. The optimal memory setting for users with 128 MB+ is approximately 1.5-2 times the RAM size, users with 64 MB should use a 2 times multiple. You should also locate Virtual Memory on your fastest drive or striped RAID volume, placing it on the non-boot drive, can help increase performance. Defragment after setting this to minimize fragmentation and force the swap file to get located on the fastest part of your disk. Third party defragmentaters can optimize the swap file.
Hard Disk Defragment
Make sure you regularly defragment your hard drive with a defragmenter. Windows XP includes one. Keep your drive defragmented as a drive with even 5% fragmentation can be very inefficient.
Besides the hard disk, make sure you regularly defragment your system registry. A handy free tool from the following site will defrag the Windows registry. Free Registry Defrag
Offload processor tasks to network adapter's with intelligent
Open RegEdit and Find HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
Edit or Create the REG_DWORD key "DisableTaskOffload" and set it to 0 to Enable the Task Offload. By default, if this key is present, it's set to 1 to disable the task offload.
Shortening Menu Delay
You can shorten the delay when menus open up by using Regedit to edit: HKEY_CURRENT_USER\Control Panel\ Desktop\MenuShowDelay By default, the value is 400, but changing it to a smaller value, such as 100, will speed it up.
Tweak Windows Vista
For tweaks, tips and tricks for Windows Vista, please check vista tweak site for how to tweak vista.