Help with Microsoft Office 11 on MAC

Screen shot 2012-04-17 at 8.42.12 PM.jpg
Screen shot 2012-04-17 at 8.42.12 PM.jpg

Hi all! today i installed some updates. my office programs are all fine except for Excel. Excel shows up on my toolbar but i cannot open the programs or files. it is saying The file could not be accessed.

i dont know what to do. i never changed the names of the files.... i am not THAT computer savvy but i can follow directions well. if someone can point me int he right direction, that would be great.

I have a Mac Book.
Screen shot 2012-04-17 at 6.07.45 PM.jpg