The other day I took my friends hard drive home with me to erase the drive and put a new OS on it, I did this using my computer, after I was done I made sure everthing worked fine, it did. Now, I try to put this drive back in my friends computer and it won't boot past POST. I checked the bios and IT DID recognize the drive, but it won't boot. I went and put this drive back in my computer and it works fine. Now I took another hard drive and put it in my Friends computer to verify it's not a bad hard drive controller, the drive works fine in it. Can anyone tell please tell me why his hard drive which I prepared on my computer will not work in the original (his)computer anymore. Thanks (the jumpers are set correctly) (tried different boot orders) (set cmos settings back to default through the cmos setup) (should I try pulling the cmos batter out, will this work)?