driver recog on other drives partitiond

A friend has partitioned his hard drive into three drives.
Has put Windows onto one drive (C) and the data onto another drive etc.
Now he cannot access fonts from C: to his D: drive using Corel.
He cannot access other programs from other drives he says. I have not seen his computer, is there some path he has to enter into his Config.sys???
I think his OS is WIN 95