Because you are looking for a free software that scans the PCs on the network for the software installed on each of them, I sugest you use the pslist.exe from sysinternals. It's the best, and although winfingerprint is a great tool, it does not do what you are looking for.
If you're asking for technical help, please be sure to include all your system info, including operating system, model number, and any other specifics related to the problem. Also please exercise your best judgment when posting in the forums--revealing personal information such as your e-mail address, telephone number, and address is not recommended.
Scan Software on Network PCs
Any suggestions.