OSDev.org

from what i understand a 64 bit OS need a 64 bit CPU, and would not work on a 32 Bit CPU.

And currently there is AMD 64 bit and IA64, so if i want to program a 64 Bit OS, and i am stuck....

anyway what advantages are there using 64 bit instead of 32 bit??

Well, simply put, the advantage of having a 64 bit OS is that it runs on a 64 bit processor without relying on slow compatibility features.
If you don't plan on using a 64 bit processor, not much sense in making a 64 bit os.

The "Thing" about 32-bit operating systems is that, although 32 bit processors have been widely available since around 1988 (original 386 specs are from 1986), "real" 32 bit operating systems did not make a widespread appearance till about 1995. And no, windows 3.11 "enhanced mode" does not qualify. As a matter of fact, win95/98/ME barely qualifies

As a matter of fact, win95/98/ME barely qualifies

For being Operating Systems?

SCNR,
citizen428