After running Defragger 1.16 and rebooting Norton 2010 internet security would not run and had to be reinstalled. Again after running it 2 weeks later Norton crashed again and had to be reinstalled. Also this time Google Earth became corrupted and had to be reinstalled. Windows XP SP3 Sony machine with 3 gig dual processor and a 200 Gig hard drive only 30% full. This problem only happened on the first startup after running Defragger 1.16 each time. Scan Disk reports no errors.