When trying to install a program, I received the message "C

Windows\system32\OLE2.DLL is not a valid image..." I asked my friend Google and found 1.9 million entries, waded through the first 25 and was even more confused after that.
Any help for fixing this would be greatly appreciated.
Brakes
Dell Dimension 4300, Intel Pentium 1.6 Ghz
512 MB RAM
XP home, SP3