The latest DAT file I currently have on my computer is 5576. However, the McAfee site shows 5577 as the latest file. When I click Update, I am told I have the latest protection. I have run the McAfee Virtual Technician and it reports no problems. I have also uninstalled and reinstalled Security Center per the recommendations given me by tech support. Neither solution gave me the latest DAT. Is 5576 the latest others are showing? I have never had any problems previously getting these DATs. I am using Windows XP SP3. Thanks for your help!!!