command for listing installed applications

there are two methods (or more?) to do this with a script. One looks at the same list as appwiz.cpl the other from another registry area. Neither will give you 100% accuracy. Here is a link with a couple of examples.
http://www.microsoft.com/technet/scriptcenter/csc/scripts/software/installed/index.mspx

Open the command prompt and change into the program files directory then type "dir | more" to list the applications that are installed or you could type "dir > apps.txt" to redirect the list to a text file named apps. If you take a look at the "dir /?" you will find many other flags that you can use to gather other infomation.

Other than that you will need a script.