I'm trying to repair a Dell Inspiron 5150 for a client who thought the hard drive was bad. I ran microscope on the "bad" hard drive, and found no errors, but replaced it anyway for good measure. I installed Windows XP sp2, and everything was fine. I downloaded all the necessary drivers from Dell to a usb drive so I could install them on the laptop. I plugged in the usb drive and got an error. "error loading newdev.dll %1 is not a valid win32 application." About a minute later the computer rebooted itself. Now the loading bar on the Dell splash screen get's about 95% done, and I get a message saying "Primary hard disk drive 0 not found no bootable devices--strike f1 to retry boot, f2 for setup utility." If I enter the bios, on the first page under Primary Hard Drive: it displays none. I removed the hard drive, and reseated it, and I still get the message.