well, the way the copywright works is this. it USED to be just bios, when installing the OEM cd checks the bios for key information. if it matches, then it continues the installation. if it doesn't, it halts the installation. causes a real problem on some systems if a bios flash has ever been done. now, if it looks at the bios for the hardware config and matches with the install log and its different, same thing will happen. poor way for them to do it, but its not unheard of. I would contact them and TELL them that you installed a new HDD (maybe you updated bios??!) and now its locked out due to the bios verification. Now, if the new HDD is external (USB), then no you cant install o/s and run off of it. It would be for data storage ONLY. The way a thumb drive would be. You COULD add the drive to another laptop. Unsure how you would go about that, though. If it was modulure than all you would need to do is find a lap top with another modular bay and hook up that hard drive in... say, the cdrom spot and it would become the D: drive. However, since its internal that may not be so easy. I would try, regardless. Just chain it with the IDE as a secondary drive and the other laptops drive as the original. Careful to not fry anything (ESD and the sort)! Best bet is to tell them that its having a problem with the bios ver of the OEM installation cd due to new hardware configuration and possible bios update. Or, you can find a NON OEM windows cd and install it that way. May want to make sure that when you hooked up the new hard drive, you're IDE connection is correctly fited. Bios and installation may still see it, but may not be able to write if all pins are not seated on the cable. should be keyed, but you never can tell.