At the top of the window that opens up, click on View then Folder Options.
(For newer systems, click on Tools then Folder Options.
Select the File Types tab at the top of the new window and scroll down to
Adobe Acrobat Forms Document and select it.
Click Edit.
In the next window, click the word Open in the Actions text box and then click Edit.
A new window will pop up. (Editing Action For Type)
In the bottom box of that window, add a space after the existing path to Acrobat Reader
and add this command to the end of the path: "%1" (Include the quotation marks)
Ex: "C:\Program Files\Acrobat\Acrobat.exe" "%1"
Click OK
Click OK on any remaining windows and close your My Computer Window.
Your computer should now be ready to handle Adobe Forms Documents.