I have Itunes installed before. When I was ask to update I got this message. "Itunes was not installed correctly. Pls. reinstall Itunes. Error 7 (Windows error 126).

This is my first time to sign in at the Apple Support Community. I have a question, "I have Itunes installed at my Windows Vista desktop before and it was working. I was asked to update Itunes. Now I think I lost Itunes. Message given was, Itunes was not installed correctly. Pls. installed Itunes. Error 7 (Windows error 126)?

Does any one knows the solution to this message. I tried four times reinstalling and still getting the same message?