Can I have a unattended installation without a product key?

Sure,

but it won't be unattended.

which means the setup will be prompting u for a serial key during setup....

yeah... and won't continue without a key!!

and the MAIN reason everyone started making unattendeds if actualy to avoid typing in the serial over and over again.

yshimizu, if what you are looking for is a way to make setup unattended for the key alone (that is, it should ask you for everything else, but not for key), then see this topic:

winnt.sif for only key

@others

I suppose the words in his post led you to mis-understand what he was saying.

Prathapml, then how does that become an "unattended install"? I believe he wants to be prompted for the cd-key.

Prathapml, then how does that become an "unattended install"?  I believe he wants to be prompted for the cd-key.

Or maybe wants to be prompted NOT for key, but for all other things...

dunno... posts having clearer phrasing would certainly help...