Measurement of the $W$ and $Z$ Production Crosss Section with the D\O\ detector

We present a measurement of the $W$ and $Z$ production cross sections in $p\bar p$ collisions at 1.96 TeV using the D\O\ detector. These measurements are a test of NNLO QCD predictions and are sensitive to the proton structure. A measurement of the $W$ width can be extracted from the cross section ratio.