I am using both SQL Server 2008 and 2008 R2, I have a situation where I need both on the same computer and in same user.
But with the different versions.
I w
Yes of course you can do this. Also, there's nothing special to "guide you" for installation - just install them.
The only point you need to be aware of: if you have multiple versions of SQL Server installed, they have to have a separate instance name (which you pick at install time).
By default, a "regular" SQL Server installs as a "default instance" without explicit instance name. SQL Server Express by default uses the SQLEXPRESS
instance name.
So basically: yes it's totally possible, just pick separate instance names for both installations!