Question

Some SQL Server 2005 and 2008 questions.

1) Can they coexist on the same Windows 7 machine without issues?

2) Can you attach and run 2005 databases to SQL Server 2008 without compatibility issues or is this a no go?

3) Does SQL Server 2005 even work on Windows 7?

Answer 1

1. Yes, both can coexist on the same machine without issues.
2. Yes, however, once you attach a 2005 database into a 2008 instance, you have upgraded it to 2008 never to go back to 2005 unless you export the data into some universal format. You can however, have both engines running simultaneously and can use either set of management tools to see either database (although some features will only work with the 2008 management studio working against the 2008 database)
3. Yes. Both sets of tools (including Management Studio) and services can coexist on the same machine (I have this very setup). The only thing you cannot do is to have both engines listening on the same port. Thus, one of the two will have to be a named instance.