If you are getting a message that says you need to reinstall Adobe or use a newer version, it's likely that you are trying to download/open a PDF-E file (or a special PDF portfolio) with the browser. This should be an easy fix! :)
You need to make sure you are actually saving the file to your computer instead of opening it from the browser. To do this, right-click the file and choose "save", "save as", etc. Then from your computer you should be able to just open the file like any other. If it is still giving you trouble though (perhaps because your computer is trying to use something besides Adobe to open it), you need to right-click the file and choose the option that says something like "open with" and then choose Adobe.
If this doesn't seem to help, please send us a support ticket.