It's possibly malware and you could run a few tools such as Stinger and malwarebytes Free linked in that last link in my signature below.
However it sounds more to me like registry corruption. Have you been running Registry Cleaners or Optimizers? They are guaranteed to do something like this eventually.
I would try uninstalling all McAfee via Control Panel > Programs > Uninstall a Program (Add or Remove Programs in XP)
Run the MCPR cleanup tool listed under Useful Links at the top of this page.
Reinstall your software from your online account
The problem is i can't unistall it, as i have said in the begining when i try to do it, it said something like misp:://mscjsres::unistall.html/ cannot be found( Beacause my programme is a chinese version, i don't know the exact English wording.)
I think in this case it would be best to contact Technical Support, it's free by phone or online chat and linked under Useful Links at the top of this page. There is Chinese support there.