I am using Windows ME and when I began to open a PDF recently, I got an error message stating that Adobe Reader may not work properly unless I upgrade. So I upgraded as instructed to AdbeRdr60_enu_full. When I installed this on my system, I could no longer open PDF's. I tried to reinstall and what happened was that my old program ("C:\Program Files\Adobe\Acrobat 6.0\Reader\AcroRd32.exe") was reinstalled. I'm able to open PDF's once again but am concerned that I may be getting limited functionality as well.