just lost my itunes after doing a update. getting error message MSVCR80.dll and ERROR 7 (Windows error 126)I even tried to reinstall the whole program off from here. What happened? HELP!

I tried to open my Itunes toady on my home computer. It said to update the library so I did. Now it wont open or anything. Tried reinstalling everything and get the error messages posted in the title above. Please Help. I have a lot tied into Itunes. Now when I check for updates it says everything is upt to date but when I try to open it i still get these two erroe messages. MSVCR80.dll and ERROR 7 (Windows error 126)