New tb sata drive not booting

So you had a system running with an IDE drive as the boot device. Then you installed in it a new 1 TB drive on a SATA port, installed on it Win 7, and disconnected the IDE drive. Now it won't boot.

My guess is that you did NOT tell the BIOS that you wanted to change which drive to boot from. Obviously it was set originally to boot from the IDE Primary Master. With the changes you made, you need to go into the BIOS Setup screens and adjust that setting. When you boot the machine, hold down the "DEL" key until it boots into the BIOS Setup. Within it there are several menus where you set things, and one of them (often the Advanced Settings Menu) has a place to set the Boot Priority Sequence. Usually there are separate steps to set the first device, the second, etc. Assuming you have no floppy drive but do have an optical drive, I recommend you set the optical drive as your first device. When you boot, if there is a bootable disk in the optical drive it will boot from that. But if it is empty, the BIOS will proceed to the second device. For that I suggest you ensure the second device is your new 1 TB SATA drive, and not the old IDE Primary Master. For third and later devices, set to None so it does not try anything else.

Elsewhere in the Setup menus, usually in Peripheral Devices, there should be a place to set details of how your SATA device is handled by the BIOS. You may have choices of IDE (or PATA) emulation, native SATA, AHCI, or RAID. Since you're running Win 7 here you could use any of those first three; do not choose RAID unless you plan to create and use a RAID array. I'd suggest native SATA is a good setting for your case.

Once this is set and it runs properly, you could re-connect your IDE drive. With the BIOS set to boot from the SATA port and use it as the C: drive, it will treat the older drive on the IDE Primary Master port as just a second hard drive to use for data, etc. It will not try to boot from it unless you go back into the BIOS and set it to do that.

In that case, choose IDE. (You may have done this already). This makes the SATA device appear to Windows as a plain IDE device that all Windows versions understand with no trouble.

AHCI is another drive interface standard that adds certain functions like hot swap support, task queuing, and I'm not sure what else. For most desktop stand-alone users it offers few advantages, but it may require the installation of driver files in order to work.

Now, if your system is set to IDE treatment of the SATA drive and to use the SATA device as the boot device and it still does not work, I'm a bit puzzled. Was it set that way when Win 7 was installed?

I assume you have not been able to use the Win 7 installation at all since it is not booting that way. In that case, a re-install of Win 7 would not cause you to loose anything - it would just take time. Are the Win 7 installation files on your old IDE drive, or burned onto a bootable optical disk? If on optical, I suggest you ensure the older IDE drive is disconnected so that the new 1 TB SATA drive is the only HDD in the system and set to IDE mode in BIOS, the re-install to it. At the beginning, ensure it is told to Delete all existing Partitions and start with a blank new HDD condition. Installing to the only HDD in the system sometimes avoids subtle errors in the installation process.