As well as exclusive access to the database, try these ideas:
1. Close the database, and check in the same folder for a small ldb file
with the same name. After a crash, this may contain spurious locking
information, and prevent you from changing the forms. Delete the file.
Restart Access.
2. If the database is secured (mdw), do you have permissions?
3. Uncheck the Name AutoCorrect boxes under:
Tools | Options | General
Explanation of why:
http://members.iinet.net.au/~allenbrowne/bug-03.html
4. Compact the database to get completely rid of the name auto-corrupt
stuff:
Tools | Database Tools | Compact
5. Decompile a copy of the database by entering something like this at the
command prompt while Access is not running. It is all one line, and include
the quotes:
"c:\Program Files\Microsoft office\office\msaccess.exe" /decompile
"c:\MyPath\MyDatabase.mdb"
6. Compact again.
7. If you are still stuck at this point, get Access to rebuild the database
for you by following the 6 steps for the first symptom in this article:
Recovering from Corruption
at:
http://members.iinet.net.au/~allenbrowne/ser-47.html