What do you mean by "Loses harddrives"? Do you mean your secondary/not-primary drive doesn't show up in Windows Explorer, or that your main boot-drive just doesn't work?
For the former, it could be that your motherboard's particular socket which that drive is connected to, has died (or the cable). Try seeing if you can place it in another socket or a different HDD cable.
...Actually, are you placing the other drives in master/slave sockets without having changed their jumper/thingmie that controls that? Might be worth checking.
Gi'es a try and then post your result.
what I mean losing master and slave hard drives. dosen't see them when boot up. I changed motherboard, hard drives, memory cards, sata cables before this happened for some reason I just unplugged them and plugged them back in and now its working fine has been for several days now I'm stumpped.