Keep Windows XP operating data in the main memory

Windows Xp in its default settings store essential driver files, kernel files to the virtual memory. As virtual memory is in harddisk system will suffer to quick access these files. But you can change settings to this memory management. Remember you should have more than 512MB of RAM and otherwise it may result in an unstable system.
Start>Run
Type regedit
Navigate to key
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control
\Session Manager\Memory Management
And change DisablePagingExecutive value to '1'.
Try this at your own risk.