I have Windows 7, use avast! antivirus, and explorer. Computer hard drive had to be replaced recently by Dell. When I got it back, I installed Reader right away. At first, it gave me the same problems I have now - but eventually a file I tried to load asked for permission and I was able to tell it to always allow Reader to load. After that, the PDF's loaded fine. Then there was an update and ever since, it doesn't work. If I simply try to load Reader - it will open for a few seconds, then close without any error messages. If I try to open any PDF files online, it acts like it's trying to load them but never does. Again, no error messages. I have tried loading lots of different PDF files, but never been asked for permission again. I have tried using the Adobe tool to remove all old versions and reinstall. I have tried registry keys given in other discussions. I have run several malware programs. I am at a total loss at this point. And I *really* need my Reader, as I have tons of files that are PDF (like my taxes). Thanks SO much for any help you can give!