Running windows vista home premium 64 bit I was attemping to open a pdf file from a web page that I created approx 1 month ago. I didn't see that and update had been completed, however I was running reader 9.0. I for what ever reason was not able to open any pdf file's off the web site like that I did before. I spent hours looking for the answer. Using microsofts windows cleaner, updating the registery, uninstalling all the adobe products except for my CS4 design products. Still was unable to use reader 9.0. After reading some of the forums I just downloaded reader 8.1.3 and it works fine. I had tried using reader 8.0 on avant microsoft web browsers and neither of them worked. 8.1.3 works fine. Just uninstall everything and download 8.1.3 until adobe can fix the issue. I had also called tech support and they referred me to the site after being on hold for 45 minutes, I could barely understand the guy... Hope this helps this is were I downloaded 8.1.3.