no windows components use the framework. Most programs use .net 1.0 or 1.1 as it is the most common denominator. 2010 is heavily themed and possibly uses some calls that require a newer framework. I had an issue with 2.0 once. It wasn't fully compiled and installed services to compile the framework during idle time of the system, which i don't ever have, due to media software. I had to research how to force the compile.