Summary:  This article discusses how to uninstall software using GUIDs.  Silent switches very from vendor to vendor.

NOTE:  Adobe Reader 9 is the example used in this article

To uninstall Adobe Reader run: 

msiexec /x{AC76BA86-7AD7-1033-7B44-A90000000001} /qa

 This successfully uninstalled Reader using GUID and silent switch

How to Obtain The GUID:

1. Open a command prompt.

2. Input WMIC and press Return. You will see a prompt that looks like this:

3. At the new prompt, execute the following command:

product get name

This will generate a list of installed applications.

4. At the prompt, execute the following command:

product where name=""

where application name is the name of the program you wish to uninstall (use the exact name provided by the previously generated list).

For example, if I were wanting to uninstall Adobe Reader 9, my command would look like this:

product where name="Adobe Reader 9" call uninstall

5. When prompted, input y to confirm that you wish to uninstall the application and press Return.

The application will be uninstalled.