Home Networking in Five Steps:

Make sure that each computer has the same "Workgroup" name:
Click: Control Panel - Network - Identification tab.

If not listed in the Configuration screen, add NetBEUI. It's explained at the bottom if you want to know what NetBEUI is.
Click: Add - Protocol - Microsoft - NetBEUI
Now for the "Properties" of NetBEUI, make sure that Client for Microsoft Networks and File and printer sharing for Microsoft Networks ARE checked.

Enable "Sharing" for each drive.
On your desktop, click My Computer -
Click ONCE on the drive to be shared -
RIGHT-Click and select "Sharing" -
Check the "Shared As" box.