there are two things that come in my minds. First of all (and the one I think you are talking about) is the register edition (regedit). This contains all the strings needed by the program to run programs. It contains many information about the program to be launched, the liscence... You can access it by running it (start/run/regedit)
The second is what suggested alok. The computer management can be found by right clicking on the workstation icone, and selecting manage. This is also a very powerfull tool.
However, I wouldn't suggest you to use any of these before you aquire a certain comprehension of these tools and of the operating system as they can both ruin the stability of your operating system and your computer application.