lauramendenhall6:
Was the operating system where you had Arc 10.1 installed different from the operating system where you had Arc 10.0 installed?
I have found that a Windows Server 2008 machine has higher security settings where, even though I am a local admin on the machine, I still need to explicitly tell the machine that I want to run software As Administrator in order for the software to work properly.
bumped into this on 10.2 and Shelby's solution fixed the issue.