I had to replace my hard drive, XP pro sp3, and all my applications - including SQL Server 2008 R2 developer edition. My databases are all on a separate physical drive. I find I cannot move or copy them to a different folder, I cannot flip the read-only flag, and I cannot attach them to the database server.
I am logged in as administrator and accessing management studio as sa. None of the other user files are write protected on that drive.