basic and dynamic disk problem

i have an old P 200 MMX. I installed Windows 2000 pro on it an everything works fine, but when i tried to convert my basic disks to dynamic, I could not see the options on the menu. My comp was not a laptop! I search the registry and everything seems fine! I have two disks, one with 3.4 gigs and one with 17 gigs, all IDE.

Any idea?

Thanks!