Will it work 1 tb hdd in intel D865GSA mother board

A 1 TB hard drive will work with your motherboard. You could even connect two if you wanted.

For the best speeds, get a SATA HD that spins at a minimum of 7200RPM.

Yes a 1 TeraByte Hard Drive will work for your intel motherboard.
http://www.intel.com/products/motherboard/D865GSA/
The link above shows what your motherboard can handle. Any Hard Drives now can operate smoothly on any motherboard. You can only limit your RAM or memory from the motherboard. It can only handle 2GB of memory, but your fine on Hard Drive space and lots of memory. If you plan on a new Operating System, I suggest sticking to Windows XP or Vista. 3GB is required for Windows 7 operating systems. I hope this solves your issue of installing a new Hard Drive to old motherboard.