comparing live database and a backup file

hi there,

i am working with the trial version.

when I try to compare a live database which is on my laptop with a backup file of a fairly similar database which is on my desktop, i get an error message saying:

The trust relationship between this workstation and the primary domain failed,

It seems to have a problem with the back up, as the program runs fine when I compare two lives databases.

Any advice given would be much appreciated

Damien.