Windows XP SP2? Did you upgrade from SP1?
You might as well have My Network Places on your desktop(*). I do.
Right-click on the desktop.
Click on the Desktop tab.
Click Customize Desktop.
Check the My Network Places check box.
You'll have My Network Places on the desktop. Open it and:
In the side bar, click on View Network Connections.
Right-click on the icon for the LAN connection you have.
Go to the Advanced tab.
This is where SP1 should have a firewall check box, I believe. I've seen SP1 corrupted to the point of not having this available with an apologetic message in its place. This upgraded to SP2 shows no sign of foul play, but the firewall will block random things with nothing to do but to reformat.
In SP2, click on Settings. Just turn the thing off and get ZoneAlarm from http://www.zonealarm.com/
I forgot to mention network drives. In any folder:
Click on Tools.
Select Map Network Drive...
Choose the letter for this network drive.
It should be some letter that will never be used for anything, not even a flash drive that is not yet plugged in. If you plug in a flash drive, unplug it, assign that flash drive'* letter to the network drive, the flash drive when plugged in later on will not show up any more. Reassign a letter at the end of the alphabet for the network drive to make the flash drive show up again.
Sam right-clicked on his C: drive in My Computer and went through the procedure to make that shared. It shows up as a shared folder called drive. For Bob'* computer to have drive Z: show up to show Sam'* C: drive:
Type in \\192.168.1.3\drive
Now, you can go on Bob'* PC to My Computer and open the Z: drive. This will show the entire contents of C: on Sam'* PC. Suppose that Sam has shared his folder called More Bonneville Pictures with the shared name Bonneville. Bob can now map \\192.168.1.3\bonneville to drive letter W: In My Computer on Bob'* PC, W: shows Sam'* More Bonneville Pictures folder contents. It'* pretty cool.