ISmRoI

Hello All, i already deploy windows 10 without any issue on my lab and installed on C drive but if i have used PC and have some files on D drive or other drives how can i deploy it without format the D or other drives and keep the file save, i check the option on task sequence about the partition disk i can leave D drive and make fix size for C only but i test it on my lab and the D drive become unallocated or ask for format mean all the data are, any one have idea about this issue ? Thanks