I have two computers. One has a single monitor and the other has two. I want to be able to switch between both using a single mouse and keyboard. I can't install software on these comps so it would be an external switcher. Any help is greatly appreciated.
Yeah, my own suggestion was going to be along the lines of asking if one or both of the PC were on a Pro OS, and then you can use RDC. Even at that there are certain limitations of the things you can do that way.
Plug monitor(s) into whatever PC(s) you want to see stuff on. You can have multiple PCs connected to a given monitor (cable from each PC to each monitor). Just select the input option on the monitor to see whatever PC you want.
KVM switches are horribly antiquated and/or grossly overpriced.