We began with Deep Freeze Professional a year ago, and have not needed to rebuild or re-image a single PC in our 150 seat lab. The students are set up as administrators and unfortunately, they install all sorts of nonsense. We even had a huge outbreak of the Blaster and Welchia virus but our PCs were the ONLY computers that did not retain a lasting infection. It's true that the virus appeared on about 30 of the machines, but 20 minutes later when the PCs reset themselves (due to the Deep Freeze Idle-Time Restart feature) the virus threat was completely gone. During the Deep Freeze Maintenance window we were able to disconnect the computers from the network, install Microsoft patches and update the anti-virus product, and less than 2 hours later we were back on track. That was over a month ago! Since then virus threats have been zero in our area despite the fact that they're still running amok all over the rest of the campus!