Hi again, merk,
I wasn't thinking clearly when I wrote the above reply. By far the easier option is to keep "c:\program files\bb" as your working directory as all pointers to Realtracks and Realdrums are present.
All you really need to do is to delete ver. 2011 and reinstall it. When you do, make sure that you insert the path "c:\program files\bb" wherever you see "c:\bb" in the install options. I guess Realband will be "c:\program files\realband".
While my previous solutions would work, this solution is simpler.
Regards,
Noel