PSINFO will give you some great information about machines on your network, you can find how long a box has been up, the installed Operating System, Service Pack, Windows Updates, other installed software and basic hardware information.
Download the PSINFO executable from http://technet.microsoft.
Then open an Administrator command prompt (you may need to use runas).
At the prompt type “PSINFO \\machinename” to get info on a server named Server01 in type PSINFO \\Server01.
Putting a -h before the machinename shows installed hotfixes.
Putting a -s before the machinename shows installed software.