I plug in my new microwave into a outlet and everything went dead.I check fuse box and fuse was OK.So I went out and bought a tester to see if outlet was hot,when I plugged tester into the hot and neutral I get nothing, but when I test hot and ground the light on tester lights up. The thing that I don't understand is the outlet was working for 8 years without a problem.

The ground is NOT hot. That is just showing voltage hot to ground.
What you have is an open neutral somewhere. You need to check every device on this circuit for a bad or loose connection at the white wires.