Non-destructive repartition

I have a WIN95 computer that has a 2.5GB hard drive. It is partitioned c:1.3GB and d: 1.2 GB. (It came this way from the VAR.) The d drive is empty and the c drive is full. Is there a utility whereby I can add the d drive space to the cdrive partition wothout detstroying the data and OS on the c drive? I know Fdisk won’t work. I have Gdisk but am not familiar with it yet.

TIA…
David