Opening files by draging from windows Explorer to desktop ..

I have recently posted this in the media centre newgroup but I think this is
a better place.

Up until recently I was able to drag files from Windows Explorer onto the
desktop short cuts and have the application open the files. For the last few
days this process has become unavailable. The symptom is that the cursor
changes to the no-entry cursor and the file is not accepted. I have tried a
Windows Restore without success. Does any body know how to rectify the
situation?

Thanks