I have Windows 7 64 bit, and recently upgraded from Home Premium to Professional. The upgrade worked in general (it now says I am running "Professional"), but one of the "Professional" features I wanted to get is not working. When I go to Administrative Tools and try to open Local Security Policy, it says "MMC could not create the snap-in. The snap-in might not have been installed correctly. Name: Group Policy. CLSID: {8FC0B734-A0E1-11D1-A7D3-0000F87571E3}".

Although it mentions Group Policy in this message, the Group Policy Editor seems to open correctly.

I also get a similar error when trying to open Print Management, but all the other items in Admin Tools open correctly.

What is causing this, and how can I fix it?