1. Install SQL Server 2008 in a new box. 2. Either backup existing database from 2005 and restore back on on 2008 -it works fine. 3. Either detach existing databases, copy them over to 2008 box and attach them. This also works fine. 4. Use SQL Server data transfer to transfer the database. 5. Generate the script for the existing database, and recreate it on 2008, BCP out the data from old one and pump it back to new one. So take your pick. Personally I will use either 2 or 3. Note that once you have upgraded the database to 2008, it cannot be attached or restored back to 2005.