At times like this, nothing beats a good backup.  In fact make a complete
backup of your database now and put it away for safe keeping.

Tony Toews has an excellent web page on database corruption.
http://www.granite.ab.ca/access/corruptmdbs.htm

Allen Brown also has excellent info on corruption.
http://allenbrowne.com/ser-47.html

I have a white paper in a Word document named Fix Corrupt Access Database
towards the bottom this page:
http://www.rogersaccesslibrary.com/OtherLibraries.asp

I'm assuming in the above that the database file is corrupt. It's also
possible that your PC was messed up with power outages. You may need to
uninstall and reinstall Office. I had one case where we wiped the hard drive
and started over from the computer's recovery disk. In another case it was
just easier to buy a new computer.

At what point does the error occur? When you're opening Access, opening the
database, trying to do something in the database?

Try going to Start... All Programs... and navigate down to msaccess.exe (you
might need to do a Search in Windows Explorer instead). See if you can open
Access without opening ANY database - that will at least narrow down the
possible problems.

            John W. Vinson [MVP]