Help on Uninstall Script for Acrobat 9

Hi, I am having trouble developing a script to silently uninstall Adobe Acrobat 9.0. In the registry editor, I notice there are two entries for this program only one of which has the uninstall string, which I find odd.

 

When I try to run that msiexec /I {AC76BA86-1033-F400-7760-000000000004}, it simply pops open a dialog box with information about the msiexec command.

Has anybody encountered this before? Any tips on how to uninstall successfully would be greatly appreciated, I'm still quite new to PowerShell scripting. This should be easy to do with the msiexec command no? Or is there a better way? It is a 32 bit version of acrobat btw.