I loaded vista ultimate on my system with no problem and I was adding some other software to the system. I notice that I the system was asking for some virus Protectioni software so i loaded it in and when the system rebooted it said there was an error. the system can not boot it will not come up in safe mode. It ask for a reboot disk I do not have one. how do i get a reboot disk? can I use the upgrade cd to reboot?