I have a brand-new computer that was operating OK when originally installed (mostly; had some erratic boot failures), but went down when I tried to install an HP Photosmart C5280 All-in-one Printer. The system displayed a blue screen message that it experienced an error and shutting down. Subsequently the computer will not boot. It fails erratically at different points: 1) most common- does not make it to BIOS setup and throws a variety LED codes on the MB; 2) makes it to BIOS set-up screen but hangs while "Detecting arrays"; 3)makes to the BIOS setup/enter set-up, system hangs in 1st setup screen; 4) system begins booting, displays a table of devices, then a message "The file is possibly corrupt. The file header checksum does not match the computed checksum" Once the system has hung, it goes nowhere in the boot sequence until the system is powered down for at least 15 min. It seems to me like plugging in the printer corrupted boot parameters. I've been trying to run the system restore CD or Vista setup CD but I can't get the system to boot far enough to read off DVD devices. On one occasion I got as far as a prompt to boot from CD, but the system immediately hung. Any sage advice??