does micro center have kvm or kv switches to connect one keyboard or mouse to two or more computers;one pc is a dell windows 7, the other is a dell windows xp?

The KVM products by IOGear and Trendnet have been working well for me and are good value. Be sure to get the right cables for the equipment that you are connecting

Yes. Many options. Almost an entire isle devoted to them.

Probably. They've got everything you can think of computer related. Best to look on their website or go in and have them help you