My Friend Magnus has a great blogpost covering the steps for installing SP2 on Exchange 2010 that rtw´d today.
What is not covered is when UM is installed and it also has a language pack that is non English. What will happen when you try to update to sp2 is that the setup fails and you are prompted to uninstall the language packs before it can update to sp2. (yes I always forget this)
To fix this error close the setup and fire up Exchange management shell and uninstalling the UM language pack.
But don’t get fooled trying to just run just Setup.com /RemoveUmLanguagePack:sv-SE from the prompt since this will fail and just give you a prompt back.
So what you need to do is to run the original setup.com and this is actually documented on TechNet http://technet.microsoft.com/en-us/library/bb124004.aspx
“You can’t use the Setup.com file that’s located in the \Bin folder to remove a UM language pack after you’ve installed any updates for Exchange 2010. You must use the Setup.com file from the Exchange 2010 DVD or the downloaded source files. If you don’t, you’ll see the following error: There is a version mismatch between the running application and the installed application. “
Ok so find that old iso and mount it and then then try running Setup.com /RemoveUmLanguagePack:sv-SE from it and you will se something different.
Ok when the UM language packs are uninstalled its time to update the Exchange to sp2, just follow Magnus guide for that.
And when SP2 is applied we have to install the language pack again, but the latest and greatest version that can be downloaded from http://www.microsoft.com/download/en/details.aspx?id=28191
And to install it, just run Setup.com /AddUmLanguagePack:sv-SE /s: d:\MyLocalFolder
(sv-SE could/should of course be switched to the language pack you are installing.)
Btw, I just saw that its now posible to just doubleclick the languagepack.exe file and then install via the gui