I'm completely lost on what to do, any suggestions?
FYI, I'm running Windows 7 64-bit.
More aboutitunes pretty screwed computer
Have you tried a System Restore? Powrpof.dll might be the wrong version or corrupt due to the update. Change the files name temporarily, download another version of the Dll copy it into the same folder and see if it works. Sometimes putting the Dll directly into the programmes folder (i.e. C\ program files\ iTunes) is a better option as the file is only accessed by that one program
The DLL may have to be re-registered... especially since the file is there, but the programs can't find it. I can't remember how to register a DLL file off the top of my head, but I'm pretty sure that's the issue.