"application has failed to start because the application configura

Had B2TR -- everything was peachy until Saturday (1/13/07)
Suddenly, on trying to open any Office program or OneNote, I get:
"This application has failed to start because the application configuration
is incorrect. Reinstalling the application may fix this problem."
Reinstalling B2TR did not fix it.
Decided to uninstall B2TR and downloaded trial version of Office & OneNote.
All of a sudden got error msgs from .NET framework (??):
"Error 25007.Error occurred while initializing fusion. Setup could not load
fusion with LoadLibraryShim(). Error: The handle is invalid."
Uninstalled absolutely everything that had anything to do with .NET
framework or Office at all.
Install of trial version finally successful (it says it has been
successfully installed)
Try to run any of the Office or OneNote trial version programs I get
same error: "This application has failed to start because the application
configuration is incorrect. Reinstalling the application may fix this
problem."
I have tried googling this error, searching KB, product support, these
communities -- absolutely zero matches for anything like this.
Frustrated is my middle name at the moment.
I don't know what to try next -- can't figure out where this is coming from.
Please help. Right now I'm having to use my husband's work laptop just to
read Word docs attached to my emails.