I would suggest that you go into the BIOS to check to see whats going on, that would give us some insight, as right now there is just not enough information to go on. Are you dual booting hard drives? If so it could be that your computer is booting to the new HD (that I am assuming is empty), not finding any information and restarting. Normally the computer should prompt you with an error but may not.
Things to look for in the BIOS, are: Installed drives and, Boot order, or Boot sequence. Some where in the BIOS it should tell you all the drives that are connected to the computer, check to make sure that the all drives that are connected to your computer shows up. The next one is boot order, you want to make sure that what ever drive windows is installed on is the primary "boot" hard drive. Some times there will be two settings, one will be a generic order Like Boot: from DVD, USB, and HD, and then there will be another menu to set witch HD comes first.
If that checks out post what info you find in the bios, or if you need more help, post bios options, maybe we can Figure it out.
The 1 TB hard disk has 3 partitions .. in C: its Windows 2003 Server , In D: its Windows 2008 Server .. But as of when i boot the system with C: also, the same problem comes .. system restart cycle starts ... As i checked the BIOS but i didn't get any kind of settings or options for this ...