We ran into a little issue where Windows Server Standard only supports 32 GB of memory, which is depressing to find out when your server was recently upgraded to 48 awesome GB of memory.
Is it possible to do an in-place upgrade from Windows Server Standard (max 32 GB memory support) to Windows Server Enterprise or Datacenter (max 2TB memory support)?
I tried kicking off the Windows Server 2008 setup.exe from within the OS, which gives me an "upgrade" option.. but when I get to the "Where do you want to install Windows" part of the process, it tells me
The partition you selected might contain files from a previous Windows installation. If it does, these files and folders will be moved to a folder named Windows.old. You will be able to access the information in Windows.old, but you will not be able to use your previous versions of Windows
That's... not... what I had in mind when I clicked "upgrade"!
I really don't want to deal with a clean OS install on our production database sever, and would much rather do an upgrade install if at all possible!
I know this question was originally regarding Server 2008, but I thought I'd post an easier answer that applies to Server 2008 R2 (and Win7 for that matter). I got the original info from TechNet Server Core blog post.
Starting with Windows 7 and 2008 R2, it's possible to upgrade editions in-place with the dism utility. You can only go upwards in edition (i.e. Standard to Enterprise) and you can't reverse the change. You'll also need the associated KMS Client Setup Key for the version you're going to. Here's a link to the list of KMS Client Setup Keys
To determine the installed edition, run:
DISM /online /Get-CurrentEdition
To check the possible target editions, run:
DISM /online /Get-TargetEditions
Finally, to initiate an upgrade, run:
DISM /online /Set-Edition:<edition ID> /ProductKey:XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
For example, to upgrade to Enterprise from a downlevel version, run:
DISM /online /Set-Edition:ServerEnterprise /ProductKey:489J6-VHDMP-X63PK-3K798-CPX3Y
I fired up a VM with Windows 2008 Standard on it, and then upgraded it to Enterprise. At first I couldn't because I didn't have enough disk space available on the C drive. It appears that 15-20 Gigs of free space is required. Once I made the C drive larger it upgraded without issue.
When there wasn't enough space it wouldn't upgrade and would require that I install a new OS much like you said you saw.
After I clicked upgrade, the installer confirmed that I wanted to upgrade then it started the upgrade. It's still running at the moment, but I'm sure it'll finish eventually.
Microsoft seems to say so: http://technet.microsoft.com/en-us/library/cc755199(WS.10).aspx
This discussion seems to indicate that it's a matter of starting SETUP.EXE from inside the existing OS, as you did: http://social.technet.microsoft.com/Forums/en-US/winserversetup/thread/a9fb29a1-9cad-4d01-9e65-ce9b2b88232b
I'd say spin up a scratch box and give it a try... (or start a community IT support site and wait for some poor addicted fool to do it and report back on whether or not it works... >smile<)
The message you get makes sense in the context, that this upgrade procedure is the same one for upgrading Windows Server 2003 to 2008. It's a warning that the old version - in your case the 2008 Standard Edition - cannot be used after the upgrade.
During the upgrade process all files, folders and applications associated with the previously installed Windows version are relocated to a windows.old folder and all user settings stored.
Once this task was completed, a clean installation of the new Windows version is performed and all saved user settings will be migrated to the new environment. A successful upgrade will include all applications, settings and user files from the previous operating system installation - in your case from Windows Server 2008 Standard.
Good luck!
As the answer is already here, I just thought I'd be the boring guy by stating that the general opinion on doing upgrades on Windows is that this is a feature reserved for home use and even then as a last resort only.
Wipe and redeploy. There are too many things that can go awry during an upgrade that are not immediately apparent.
But good thing it seems to work, I guess ;p
I ran into some problems when trying to upgrade to Enterprise from Standard because our Product keys worked for both editions. Found the reason in this blog. The blog also recommended to use a MS client setup key to do the upgrade. The keys can be found here.