Realizing that the original poster has probably moved on from this problem, wanted to post this in case it helps someone else. Apparently Windows 7 has a Trusted Installer group that is separate from the Administrator group. If a user tries to change something in a "controlled" folder and is not part of this Trusted Installer group, the system returns a "location not available" error.
I've had this problem several times. I've upgraded my daughter's laptop from Starter to Windows 7 Home Premium. After log in, the whole aero glass display is gone and it looks the desktop looks like windows 2000. What I've done to bypass or recover my desktop is that I log out and log back in and everything looks normal again.
Is there a fix to this problem/bug? Kindly assist.