For Access97 but for 2000 i think is the same thing
Each time you run access, this program is running with a "secure" file like .mdw. You must make tow thing :
1) With a program named "WorkGroup Administrator inf French Administrateru de groupe de travail" " in your Access installed Directory , verify your are connected to the system.mdw in your Windows Dir.
If no Join it
2) If the problem persist, open Access with account Admin, and reste password to blank.