Aaron Berquist solved a little issue with the GP 2010 R2 upgrade and wants to share the solution in Troubleshooting Upgrade to GP 2010 R2.
Troubleshooting Upgrade to GP 2010 R2 | Aaron Berquist – High Dynamic Range
Install, Upgrade & AdminGP 2010
Archived post from 2011. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.