I recently noticed unknown characters in the vista registry. They are only on HKEY User and are on the initial folder titles. they also only appear on the first 25 or so folders in the list. . The titles of the folders are being replaced by these characters. Ran hd diagnostic and it passed (used wd lifeguard diagnostic tool). ran Sophos virus removal and came back empty. The computer is slow but no virus indicators. Could this be previously installed security software? not sure what but I did get this computer from a friend and don't really know the history.