I run XP pro corp with the sp1 installed. It put alot of patches that were needed. Their whole "removing ie" Is a big hoax, but hey, it works fine. I use Opera browser and Sygate Personal Firewall with AVG antivirus.....No problems whatsoever, Even with the Bugbear virus running rampant like it did a while back, I had no problems. I also keep up on all the updates, so it helps. As far as proprietary stuff, I run a gateway comp and had no problems.