While uninstalling Visual Studio 2010 Beta 2 today, I ran into this issue whereby the installer failed to uninstall due to be unable to access a particular registry key.
To fix this issue, you need to click on the start button and type “regedit” without the quotes and then right click on the program and run as administrator. Accept the UAC prompt if it appears.
Press F3 to bring up the search box and search for the first five or six characters of the GUID so that you can find the registry key that’s causing all the problem
Clicking on the key will cause the following error
You can then right click on the click and click permissions. This will bring up a warning that you don’t have permissions to view the current ones, you can reset the permissions on the key.
As you can see you cannot see the current permissions on the key.
Clicking on the the advanced button will bring up a new dialog to allow you to reset or add new permissions to the key.
Click on the owner tab and you should notice the text that the current owner cannot be displayed. You can then click on one of the user groups or users to change the current owner. If there are many sub keys, you can also apply the owner to the those.
Once you have applied the new owner you can apply the correct permissions to the key and continue.
However you will need to finish the uninstall and then restart it to completely remove Visual Studio 2010 Beta 2