Sorry Guys, have only just seen this thread.
For the record, Error 0 in Access indicates an "unknown" error typically with the [MS Access] program installation or setup where installing the latest SP will usually correct the problem. Alternatively, it could be linked to file corruption in which case compact / repair both Old and New DBs.
The migrator was produced with the Dev Edition of Acc2k patched with the latest SP3. Since it uses linked tables to both old and new DBs, it is flexible enough to migrate to / from any combination of 2k / 2002 and even 97 though I have not tested the latter.
The App itself requires a full version of Acc2k or 2002. Using my own Acc2k test rig, it is NOT necessary to run the App from c:\temp although the old and new Dbs must of course reside there (paths were hard coded to that folder for expedience). If moving the App to c:\temp solved your particular problem then great but it would suggest an error with your prog setup.