PC is not booting

Hi guyz
i have two hard disk drives first one is samsung 40 GB HDD in this XP is installed and second one is Seagate 80 GB HDD.
When i connect my Second HDD i.e.Seagate my PC not booting means that blue line bar below XP logo continue to pass many time.
what should i do now ?

Well when you try to boot with your second hdd ie. Seagate 80 GB do you also connect your 1st hdd or not?
IF yes then try to disconnect your samsung hdd & see if XP on seagate boots properly or not.

I am having the exact same problem. It just started yesterday. It
seemed to happen after I ran my usual spybot, adaware, spyware blaster,
norton live update routine. After I boot up, I get a screen that flashes so
fast I can't read it, then it stays at "windows is starting up" forever,
until the screensaver starts, then if I click with the mouse the user screen
appears and I can log in just like always.

ive once had this problem and i too was thinking that it was my m/b but then i tried something removed all the cables connected to my motherboard means sata cable, ide cable floppy cable and then start my computer and then i went in the bios options and afterwards connected devices one by one and finally found that it was my hdd which was causing the problem. so what i want to tell you is that its not your motherboard but maybe one of your devices.

yes this could be due to your hardware(hdd) problem , so primary thing try to scan your hard disk,this might happened due to bad sector in hard disk. so using boot able xp disk, or partition manager or hdd regenerator try to repair it .