Hmm, wondering if it's a permissions issue. On my system I can't create a test key (using RegEdt32) under the key you're using even as an admin.

Maybe this will help: http://social.technet.microsoft.com/Forums/windows/en-US/56fed319-a532-46a4-a384-fd795998c4a3/regedit-permissions-access-denied-or-error-while-deleting-key-even-as-admin

>I selected the CMD, right clicked and selected "Run as Administrator" and still got the same error.
>
>Any additional suggestions?
>
>>>Can someone tell me why this will not work? I open a command window, and type in the following which is attempting to delete a key titled "Good Sofware".
>>>
>>>REG DELETE "HKCR\VirtualStore\MACHINE\SOFTWARE\Wow6432Node\Good Software"
>>>
>>>I do get the confirmation question as to if I wish to delete the key, I respond yes and it then gives the following error message:
>>>
>>>Windows 7 gives:
>>>
>>>"ERROR: The data area passed to a system call is to small"
>>>
>>>Windows 8 give message that it can not find the key.
>>>
>>>Anyone know what I am doing wrong here?
>>
>>A guess - you may need to open the Command Window as Administrator.