Emachine w3400 Computer just keeps rebooting

I'm trying to help out a friend of mine who has an emachine w3400 (a 754 socket msi-7145 motherboard). A few weeks ago I helped install a sata HD for him and he used it as a primary HD with his original ide HD as a slave. He decided to remove his old ide HD. After he removed it the computer will not boot using just the sata drive. He put his old HD back and still nothing. I told him to remove his cmos battery for a few minutes and then try to boot. His system would then boot to bios, but only if just the ide HD is plugged in. And even though it would boot to bios it would not boot to windows. It would boot to near windows then just restart. As soon as he tried to boot with the new sata HD plugged in it refused to boot at all. All he did was remove the old ide HD and now it's all messed up. Anyone know why??

 

Tap F8 before windows load, select "disable automatically restart...". If enabled, Windows will restart when it encounters a big problem.