When i try to start up my laptop, it repeatedly fails to boot anything. It will start the CD drive, then just sit and do nothing. After i manually shut it back off and on several times, it will then finally try to start the Harddrive, then immediately reboot. This cycle goes on several times, then it will finally boot, giving me these messages: Error 251- System CMOS Checksum bad Warning 280- Previous Boot incomplete then the options f1 resume and f2 setup. If i do f2 and reset the default BIOS, it just keeps doing the same thing. If i do f1, it brings up a screen the includes the warning PXE-E61 Media test failure. This screen goes away after a couple seconds and then windows starts, so i cant copy down the whole screen. Once windows starts, everything runs perfecly. Its just an issue of startup. The laptop is a gateway m-1625. About a month ago, the hardrive failed. I replaced it, and at the same time installed windows 7. Its been running great since, except for this problem appearing about a week ago. I have replaced the CMOS battery, no luck. Before replacing it, i tried running it without any CMOS battery, and there was no change in behavior. It acts the same whether there is a battery in it or not. Any help would be greatly appreciated.