One of the features introduced in Windows XP is called Prefetch wherein Windows caches the boot files and the most recently used application files so as to make Booting the system faster and load the previously loaded applications faster for the simple reason its been cached.
Windows XP prefetch in my words is a “Good Bad & Ugly” all packed into one. While definite advantage is that the system boot time and previously accessed applications faster, the downside is that the feature can clog the cache in itself with those unused programs and you do not have to wait for Windows loading all those application files which you may not used this time (say used watched DVD on a DVD player software and this morning all you need is to check a few word files).
The files are cached in C:\Windows\prefetch folder. The files can be safely deleted but the downside is that the next system reboot will a bit more time that it used to as it hasn’t got anything in its cache and that it needs to cache them all over again and the subsequent reboots will be faster.
There is a Windows registry tweak that can help you control how Prefetch performs or even enable and disable Prefetch in Windows XP.
To control Prefetch,
1. Click Start – RUN, type “regedit”
2. Navigate to the following Regsitry key
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters]
3. In the right-pane, look for the key “EnablePrefetcher” edit and set one of the following values as you require:
0 – Disable Prefetch in Windows
1 – Prefetch only Application Lauunch files
2 – Prefetch only Boot files
3 – Prefetch all
Say, you don’t need Application caching then simply set the value to “2″ which will prefetch only Boot files.
4. Reboot the system for the changes to take effect.