Interesting topic. Ive been looking for a software that is able to connect to a win* PC lately. Looks like I wanted to some serious hacking here, right? Partially.
Main point is to be able to (secretly) monitor a network of PCs with different operating systems.

This is what I throw in: Does such software exist? To get that straight: I do not mean to secretly install the software as well - it should be possible to completely remote control the PC that the software connects with. Let me throw this in: Does such software exist for OpenSuse? Recommendations, opinions and concerns are welcome.