Access to C:\Program Files denied

I gotta say that I am confused, bemused, defused and otherwise lost.

Running Windows XP (that should explain it) Media Edition SP 2. In my profile all works well but in my wifes profile access to program files is denied. Also in the Owner and Administrator accounts access is also denied.

I created a new user with admin rights and access to c:\program files is also denied.

WTF is going on??

Any suggestions?