Update from GW8 to GW2012

Hello,

I try to update GW8.01 to GW2012, server is OES2 SP2, GW is on nss disk.
When I check with C1 before installing GWIA my domain and PO are always in GW8.

Before I begin update I have stopped all services.

When I check MTA, he is in GW2012.

Can I just copy db2012 and after make a rebuild of data base.

Thanks for your help.

Serge