Apple Aplication Support was not found

Well I tried playing a song, but message came up saying that "apple Applications Support was not found. Apple Application Support is required to to run iTunes. Please uninstall iTunes, then install iTunes again. Error 2 (Windows error 2)". I tried out using the iTunesetup again and it gave me options of repairing it or removing it. I tried repairing it but after everything was done and I tested it out, but once again it said "{Applications support not found blah blah blah." I have windowsXp. What should i do to fix this problem?thnx