On Sun, 14 Jun 2009 13:53:18 -0700 (PDT), amateur_handman
wrote:

I would like to install an 'over the range' microwave under the
cabinet, in an area that is not over the range. Because we will not
need the venting, can the venting be turned off?

I am not sure if venting is necessary for microwave cooking. If the
venting funtion is disabled, will it affect the cooking performance?

The venting is for the range, not the microwave. Since it is not going over
a range, why not get a unit made for under counter or buy a kit that allows
you to hang a regular microwave? It will save you a bundle of money. All
you need is a shelf for a unit to sit on.