hp pavilion 7905 with nt home on board. A friend installed a dvd -/+ rw on it and after being recognized the computer put up a blue screen of death. It was shut down and could not get back onto the operating system. Never got beyong ntloader missing..so the boot record appears intact. I was able to get to the recovery console via cd-rom..installed ntloader and ntdetect and rebooted..then hal.dll was missing. Back into recovery console and looked at c:..the only files on the hard drive were the ones that I installed...60 mb of files disappeared. The hard drive uses NTFS..is the fat( i dont know what else to call it)get attacked by a virus or what. Just like to know....thanks.