On Windows Vista, installed AdobeAir update as required. "Mandatory Upgrade" removed Acrobat!

On Windows Vista, installed AdobeAir update as required. Next screen said "Mandatory Upgrade" & when I clicked on it, version 2.0 of Acrobat was removed, new version 3.2 wouldn't download error# 16820! What do I do now? Need Acrobat, but I don't know what to do next! I'm working at a small church w/no budget. so please help if you can.