I did the same thing. The solution worked.
Nathan Griffiths-187644 (9/17/2006)
I had the same issue on a dev machine - turned out I head used my own domain account as the Execution Account and when I changed my password it caused this error - and the moral of the story is never use your user account when installing software! <img src='images/emotions/pinch.gif' height='20' width='20' border='0' title='Pinch' align='absmiddle'>
cheers