Digital BW, The Print

If I have a C & D drive...can I/how do I dedicate the D drive to 
photoshop as a swap file space?  Do I benefit from doing this?

I can generally follow directions if there's a web site the walks one 
through it?

Thanks,
Cleavis

FWIW, system in use, win98se, 512ram, should be 80g HD, PShop 6