Before you can operate on an Acess databse, you first need permissions to the .MDB file.
By default, IIS runs ASP scripts in the security context of the local IUSR_<MachineName> account which has no permissions to anything on your network.
The two easiest methods for addressing this problem are:
1) Change IIS Security to run ASP using a network account instead of a local account.
2) Change IIS Security to run in the security context of the current web user.