Calm down.
You will need to provide more information than this if you genuinely want to get some help.
What is your:
- MAC or PC OS version?
- Are you working on a company network? If so, have you been accessing project files stored on that network instead of locally on your PC?
- If on a company network, does it use Roaming Profiles or virtual My Documents folders?
- Have you tried renaming or deleting your Preferences folder? (plenty of posts on this forum about how to do that)
Provide some more info and we may be able to help.