HD data transfer to other HD

I would like to exchange my current hard disk “C” (win98 OS)and all data stored and transfer all to my HD “D” and remove drive “C”. My question is – What method should I use and would my OS remain executable? I have over 3 years of win98 updates andwould not like to lose it all. Also I have tried to copy my OS to CD-REW to retain updates but it is always “un-executable”. Please help