Accessing SBS 4.5 partition

I’m running Back Office SBS 4.5 on a dual boot system (Drive C = NT4Wks SP4 and Drive D = SBS 4.5).
The idea is to do a complete backup of Drive D (my entire SBS installation)in case of a disaster.
But SBS does not allow me to access Drive D from NT4 Wks.
Is there a way to enable this ?
Help will be appreciated.
Thanks a lot.

PM