I have a dell inspiron 530 desktop PC build and my current os hard drive(250gb) has windows vista 32 bit, i have two laptops with one thats a hp having(500gb) windows 7 64 bit and a dell thats a (500gb) windows 8 64 bit. I took both the hard drives out of the laptops and put them in the desktop. the dell laptops hard drive said it had no boot drive (which i checked and it had windows 8 64 bit). So i tried the other hp (windows 7 64 bit) hard drive and it wiped the hard drive and when i turned it on it looked like it was going to start up into windows and it rebooted and i tried it again and again and it still rebooted even when i put it in safe mode and everything. I am wondering if its possible to even use these hard drives on my desktop if the dell laptop hard drive didn't work or the hp laptop hard drive didn't work for me. Thanks