Are there any error messages when you try to load the shortcuts? Or does nothing happen at all?
I would suggest running a virus scan and also a spyware scan.
For Anti-Virus, Google: AVG Free
For Spyware, Google: Spybot
Both work well and I have been using them for years!
It's interesting: a bunch of the shortcuts on my Netbook's Vista Basic suddenly stop working (especially those on the start menu). For some reason, shortcuts like this work fine (Internet, Chrome, etc.).
Shortcuts that don't work include the entire Office Suite, from Word to Powerpoint.