Vista & Windows 7 users - have a few minutes to kill? Open Windows Explorer and navigate to C:\Documents & Settings\username\Local Settings\Application Data
Now Open the next \Application Data folder. Do it again. And again. Let me know when you've reached the last one 
They must have fixed that with some updates. This is what happens on my systems:
On Windows 7
Location is not available
C:\Documents and Settings is not accessible.
Access is denied.
On Vista:
Location is not available
C:\Documents and Settings\Administrator\Local Settings is not accessible.
Access is denied.
