Create a database log of programs ran.

I have 43 computers that I manage in a Lab. I am looking for a cheap way to create a log for a database to understand the computer usage in my lab.

Basically, I need to log the programs ran on each computer on my network then compile that listing on a database or text delimited file. I can pull it into my database program to create statistics of programs used on a day by day basis.

I asked other people before and they said look on the web. Any suggestions or even ideas of what to search for. The suggestion or answer that I use will get the Points.