Tip 128: List all programs installed and listed in Add/Remove Programs
The script apps.vbs will produce a text file, listing all of the programs and Windows updates and fixes installed on the system.

Note: To avoid accidental running of the script, the scripts on this web server are stored as *.vb_ file. Clicking on the link will bring up the script in the browser. From there you can save it for later use, simply by selecting All text in the browser window and copy/pasting it into your own newly created .vbs script file.