Oh... is Me recomended to work with your specs? I'm sure it will but just asking because that may have influence. I think either your controller is damaged or your HD is damaged. Run scan disk on it and the manufactures disk repair to try to fix the damage if there is damage, or if it the controler you will have to replace the controller. Try taking the CD out and boot with the slave HD on the secondary IDE. If it shows up ok then something is worng with your controller, but since the other HD is ok then it might not be the controller. You said you have 3 computers... try the drive in question in another computer and see if it works. Also try it as a slave on another computer. Try it as a master on the Maxtech. If there is damage to the HD than try to repair it right away. If you can't fix it then immediately back up all your data on it in case it crashes soon.