When you initially installed the BES on your SBS, where was the database located, on the local machine or on a remote machine? MSDE or SQL?
Once you have managed to remove the BES installation on your SBS, you might also need to rebuild the database. As it might be pointing to the old install location.
A quick review of the installation requirements:
-Windows2k with the same service packs as the SBS.
-Exchange Manager with the same SP as your Exchange on the SBS.
-A service account (usually
) with appropriate priviledges (Send as, Receive as, Administer Information Store, View only administrator, it also should a local admin on the BES machine)
-Copy the file cdo.dll from your SBS (C:/Exchsrvr/bin) to your BES machine (c:/windows/system32) and register it.
-If you have to, then rebuild your database. My personal preference is SQL. You can use SQL Personal if you dont want to spend money on licenses. Database management is much easier with SQL as opposed to MSDE.