Side-by-side installation of SQL 2008 R2 and SQL Server 2005

My wife asked me to install a named instance of SQL Server 2005 Enterprise Edition x64 on top our existing SQL Server 2008 R2 Enterprise x64. HA! As a SQL Server MCT (besides the fact that I did quite a few installs in my time) I should have known better how to do it.

So here’s the quick list for you:

• There is no such thing as SQL Server 2005 x64 on Windows 7 x64 – if you check BOL, there’s absolutely no reference of Windows 7 whatsoever (I’ll need to check after SP4 installation, the installed version of BOL). However, as a tip for you, whatever they support on Vista, it will be supported on Windows 7. Bear in mind, though, that for x64 environments, things are going to be tougher for you.
• On Windows 2008 R2 Enterprise x64, it works like a charm, but with one little caveat: there’s no such thing as SQL 2K5 named instance on the SQL 2K8 R2 default instance. As a matter of fact, you can select to install the SQL 2K5 instance as default.

Ok, now, presumably you decided to install SQL 2K5 in the same machine with the existing SQL 2K8 R2 (I know, it’s usually the other way around). Couple of things to note:

• You absolutely need to consider installing the thing as a named instance. Otherwise you’ll run into some interesting surprises when you are trying to point to the default instance using SSMS. Ah, almost forgot, you can connect with either version of SSMS
  to either the default or the named instance.
  As a side note, I just hit an interesting bug, when I double-clicked the Notification Services for the named instance (that is the SQL Server 2005 installation) using the SQL Server 2008 SSMS (yes, sorry, SQL Server Management Studio – I hope there are no more questions about what is SSMS)
• You absolutely need to consider installing SP3 after you finished installing the SQL Server from the media; of course, you are smarter than I am, you will know that SP4 is out for more than 6 months. Oddly enough, it still doesn’t show on my TechNet Subscription.

Finally, two minor tips for you:

• How to obtain the latest service pack for SQL Server 2005 – just replace the “2005” portion with whatever you need and you’ll get to the relevant page
• I beg that you read their list of suggested improvements, as well as what’s new. Let me give you an example: “Microsoft Update upgrades all instances of SQL Server 2005 to SQL Server 2005 SP4. For example, if you have two instances of SQL Server 2005 that are running on the computer, both instances are upgraded to SQL Server 2005 SP4.” Say what???

I hope this helps.

Best regards,
io