I hope someone can help, I'm getting nowhere fast!
The problem started with being unable to view PDF files all of a sudden, it would just show a blank page, this hadn't happened before. Following the support centre advice, I attempted to download Adobe Reader 9.1 but the message "unable to open this patch, check that patch is valid or exists" kept appearing and download would cease. Following support centre again, I uninstalled the old Adobe programs from my computer to try and start again. Download won't happen, so now I have nothing. I had also previously attempted to download flash player without success.
Download, install, then run the Windows Installer CleanUp Utility. Use it to remove all previous installations of Adobe Reader, then download Reader 9.1 again from http://ardownload.adobe.com/pub/adobe/reader/win/9.x/9.1/enu/AdbeRdr910_en_US.exe and install it.
For problems with Flash Player, please post in the FP Forum.