Hi hyperlinx,
It sounds like you're trying to open the file in Internet Explorer, right?
If so:
In the Menu Bar (if this isn't showing lick on Tools, Toolbars, Menu Bar), click on Tools, Internet Options, Programs tab, Set programs button. Then, in the "Default Programs" window that opens, click on "Associate a file type or protocol with a program", in the "Set Associations" window that opens, scroll down until you see .pdf. This should be showing the "Current default" as your "word processor" program. If not, please let us know what it shows.
If it does, click on that entry, then on the "Change program..." button. If Adobe is showing under Recommended or Other, then click on it and on OK, otherwise click on Browse... and navigate to where Adobe is installed (usually something like C:\Program Files\Adobe\Reader 9.0\Reader\ and click on AcroRd32.exe, then on Open.
The default program for .pdf should now be Adobe Reader 9.x.
Close all the open windows, close Internet Explorer, reopen it, and click on the file you want to open. Should open in Adobe Reader.
Ed