speed up your pc by empty windows prefetch folder

The prefetch folder resides on your local hard disk, under the Windows folder.

%systemroot%\prefetch

-or-

X:\windows\prefetch   

Where ‘X’ is the drive letter where you have Windows installed. Either path will get you to your local system. The second path is for those who have the default installation on the most commonly used drive letter, C:\

The prefetch folder is used for speeding up your system. The way it does this is by doing the following:

• Windows XP is configured to prefetch application and program components so that when you load them to memory; it appears to be very quick.
• When XP does this the first time, it winds up copying portions of the program to the prefetch area of your local disk.
• When XP boots up, XP will prefetch portions of the files you use the most.
• XP loads all associated files, libraries, and pointers necessary to run the program in advance, the preloaded subset makes your system appear quicker.

Prefetch when unattended can also slow down your system. This is because over time

• XP will retain a copy of a portion of a program in the prefetch folder even if you only use it one time, which is not good. Since you may not use the program again, you may impact the performance of your system by having portions of a program you do not use loaded in your system's memory.
• XP systems with very low hardware resources (such as memory and hard disk space) will definitely be affected by an over-bloated prefetch folder.