1. Open Adobe Acrobat
2. Go to the Edit menu
3. Go to preferences
4. In the left panel, click on options
5. UNCHECK the box in front of "Display PDF in Browser"
6. Click OK
7. Close Adobe Acrobat
8. Close Internet Explorer
9. Restart Internet Explorer
10. Enter your username and password and you will be given the choice of opening the pdf file from it's current location, or save it to your hard disk where you can open it with Adobe Acrobat when you are offline. If you choose to open the file from it's current location, the file will open up directly into Acrobat Reader.

NOTE: If you have more than one version of Acrobat or Acrobat Reader installed on your machine, be sure to make the changes to all versions, or uninstall the versions you don't need or use.