I had been running 9.something and was upgrading when my system froze. After reboot, I uninstalled Adobe Reader and downloaded the mini-installer for both 9 and X ... neither would get past extracting the files before locking things up again. Downloaded the complete releases (9 & X) from the direct links and tried again with the same failed results. This was after a full disk defrag, scan disk, BIOS update, and attempting the install with startup programs off and all but M/S services disabled ... again, no success. Finally downloaded 8.3 and it installed without any issues. Adobe has definitely screwed something up with their current releases of 9 and X.