PerX injeector not working for me :\

Everytime i open PerX.exe it says "..You may not have the appropriate permissions to access this file" There is no PerX icon. The only thing in the folder is the PerX.exe and the reason I am using PerX is because Portal doesnt work for me and Black Cipher 5 loader d/cs in 60 secs or so in game. Please hellp me!

is this the perx from MPGH? or a modified perx? perx works fine for me...

OS?
mines win 7 64

Start > Run > control userpasswords2

see whether ur the administer!