Upgrading database to Sql Server fails: driver not found

I am using maintainDB restore to upgrade/convert the database to Sql Server and I am getting the error:

Cannot proceed with 'restore' command: A driver for the target database not found.
Please ensure you have driver jars in C:\ProgramData\JetBrains\TeamCity\lib\jdbc.

The drivers are in the directory:
Directory of C:\ProgramData\JetBrains\TeamCity\lib\jdbc

29/03/2014  09:52 PM    <DIR>          .
29/03/2014  09:52 PM    <DIR>          ..
29/03/2014  09:52 PM    <DIR>          auth
29/03/2014  09:52 PM    <DIR>          help
17/02/2012  11:45 AM             1,685 install.txt
17/02/2012  11:45 AM            14,392 license.txt
17/02/2012  11:45 AM             6,135 release.txt
17/02/2012  11:45 AM           563,117 sqljdbc.jar
17/02/2012  11:45 AM           584,207 sqljdbc4.jar
29/03/2014  09:52 PM    <DIR>          xa
               5 File(s)      1,169,536 bytes

Using Windows 2012 and Sql Server 2012
Using Teamcity 8.1.1

Any ideas why I am getting this error?