Give us a bit more to work with.
1. Check out this thread for the sort of detail that is needed.
help us help you
In particular, what OS are you using?
2. What exactly is happening when "it won't open"? Is there an error message?
3. Try moving the IP plug-ins from Library/Application Support/Digidesign/Plug-ins to the adjacent plug-ins unused folder. Put them back one at a time. On each occassion clear Prefs and relaunch Pro Tools. This process should allow you to eliminate a particular rogue/problematic plug-in.
4. Have you tried downloading the latest versions from the Digi site?
http://www.myspace.com/philogg