I received the following in email today -
I know there is a command that lists all of the security updates and patches that are installed in Windows 2003 instead normally looking into the control panel...
There are many ways to do this, but some of the simple ones are: (btw...this is for Windows 2003 Server, Windows XP and Windows Vista)
Go to a CMD prompt, type 'systeminfo'
If you loaded the Support Tools for Windows Server 2003, you can also run 'netdiag' - this tool does quite a bit more than just list hotfixes though. It is actually a network diagnostics tool that can help troubleshoot a number of network related issues. It just so happens that it also lists the install hotfixes and, I think it does a better job than 'systeminfo'.
But my favorite is the PsInfo utility from the PsTools pack written by Mark Russonovich. This one of many great tools that MS picked up when we acquired SysInternals last year. After you download and extract the PsTools, you can run 'psinfo -h' at a command prompt to get a nice, descriptive list of hotfixes installed on your systems. It also works over the network which is great for checking remote systems.