Looking for help finding remote desktop software

[Dudsmack]

My job requires the management of a couple of different offices each with a handful of computers. I'm tired of driving to the offices for simple fixes and am looking for ways to do it remotely.

Creating a VPN into these networks is not an option.

Can anyone recommend remote desktop software that:
* That can use profiles (I'd like to save a profile for each computer)
* That can support multiple connections simultaneously
* That can be installed on each machine, preferably with ZERO router changes.
* I have no budget, so I would prefer something Open Source

Thanks in advance!

[Trollsplatterer]

Well, "Teamviewer" is the one that pops up most in my experience, though I'm not that experienced with remore controling computers, to be honest.
I think you need someone on the other side to confirm your connection, though.