Today I searched for a version of ChrisControl that would work with Windows 7. I had been using this at work with XP and it is awesome for doing LAN remote control support. It allows for connection to a windows machine via RDP or VNC. VNC is automatically installed on the target machine and connects without a password. This is all assuming you have access to the administrative share of the target machine. It also automatically uninstalls VNC after the support session has ended. There is no need to have someone at the other end of the connection initiate it or accept it.
I was really bummed when I found out my version of ChrisControl did not work with Windows 7. I found out that have a new beta version that has worked great so far. If you do support, I strongly recommend this program. The beta version can be downloaded here.