Pf extension is associated with Prefetch pre-information file. You can try to open pf files with Windows XP system.

Generally, these are the system files which found in "C:\WINDOWS\Prefetch" folder. For every software there is different pf file in this folder. Windows xp checks this folder first before running any software, and it can run faster the software by using pf file. 
You don`t have to make any changes on these files, Windows only uses these for speed. 

What to use pf

Windows XP is ended then you can try windows 10

which page related to pf file

pf Related Searches

You can check related links about pf fileextension.