Typically, if a BIOS doesn't recognize a hard drive, the hard drive is dead. Unless, of course, you don't have the jumper settings correct. The likelihood that your hard drive damaged your brother's hard drive is remote, unless yours are already physically damaged and you used the same power supply lead for testing all the drives. I'm a tech and I'm up against the same message in a custom built system for one of my clients. I'm going to look at RAM. For your case, first and foremost, if you have data that you don't want to lose, back it up by installing the hard drives as slave drives in known, working systems and transferring the data. If the known, working systems fail to "see" the hard drives and/or you can't run hard drive manufacturer diagnostics, like PowerMax for Maxtors, the drives are toast. Once you have backed up, take the system to its bare bones - mb, hdd, memory - and work forward, adding RAM and other items until you encounter the problem again. Hope this helps as a start.
Kathleen Novosel
December 2005
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