Fixed this problem at last without re-installing vista am i glad of that.
I finally figured out the problem with the help of the Microsoft KB. (Thesolution was easy.)I had "Show Hidden Files and Folders" selected under the View tab of theFolder Options dialog box. I had to uncheck "Hide protected operating systemfiles"Once I did that, I was able to see the DRM folder under theOnce I was able to see the cache folder inside the DRM folder, I deleted itscontents, i also deleted cache folder was reinstated when services resumed and all was OK.I hope this helps someone else. Fortunately, no reinstallation of Vista wasnecessary, though finding this solution was a bit of a PIA.