connect the 250gb standalone on the secondary ide channel (without a 2nd device on the cable) might be some sort of conflict and remember depending on the jumper position this is how the cable should be connected mobo-->slave device-->master device , also its weird that first you had issues with your maxtor and then this one, the mobo ide controller might be faulty, if reconnecting it standalone as suggested above^ wouldnt help then try another ide cable if both didnt work then i suggest youll connect it to another pc if you got one or to a friends pc and see how it goes and if it will still be same on the other pc then i guess you really got bad luck in that case youll have to do one of the things i suggested in my first reply