Everytime I try to run one of the 16-bit programs on my hard drive within XP Pro I get an error message "16-bit Windows Subsystem" system\CurrentControlSet\Control\VirtualDeviceDrivers.VDD Virtual Device Driver format in the registry is invalid. Choose "close" to terminate the application. I can choose "ignore" and the program will run perectly. On checking the registry settings, the drivers were set to "default". I have recently uninstalled a trial of Norton Antivirus and Norton Firewall and believe there are still symantec settings active but can't find them. I am now using McAffee along with the inbuilt XP firewall.