Restoring an entire SQL Server database instance I have a server that we will be completely reformatting then rebuilding.  Everything will be rebuilt exactly as it is now - same filenames, same directories, etc.

After SQL Server is installed, I could reattach each of the databases on the server instance one by one from the full backups I've taken.

However, will the following also work to make the job faster?


Shut down the SQL Server instance
Copy all databases, including system databases, to another disk
Reformat the server and reinstall SQL Server
Shut down the SQL Server instance
Copy all files back to their original locations, overwriting existing files (would I also need the hidden Resource database?)
Start the SQL Server instance again


As long as everything is in the correct location, shouldn't the master database fire right up without issue, and the full server will be restored to the same way it looked pre-reformat?  I'm just wondering if this could save me some time.
Personally I advocate quite strongly against the detach / attach method. You're already taking proper backups, right? Why not continue that plan and use backup / restore? 

Detach / attach is dangerous, for one simple reason: if something happens during the detach or during the copy, you now have ZERO copies of your database. 

With RESTOREs you will be able to proceed even if your new server gets hosed and you need to use a different server, or you're not able to re-use the same server name, or any other host of things could go wrong.