If you want everyone to have access, this procedure will make the computer a little less secure but it works because no passwords are used and everyone is allowed access. There are three basic steps; put the computers in the same workgroup (discretionary), select the folders that are to be shared and ensure the firewall allows access. Repeat this on all the computers, use the same workgroup name but, of course, different, meaningful computer names.
XP
1. Add an XP computer to a workgroup by right-clicking My Computer > Properties > Computer Name and change the default Workgroup Name and Computer Name. The computer should reboot.
2. To share an XP folder, right-click it and select Sharing & Security > Sharing Tab > and put a check mark in Share this folder on the network and optionally, Allow Network users to change my files. Type in a Share Name > Apply > OK. A little hand should appear on the icons of the folders that are shared. Alternatively, drag the folders you want to share to the Shared Documents folder. In XP Professional you may have to turn off Simple File Sharing in Folder Options > View Tab > Advanced Settings at the end.
WIN 7
1. Add a Windows 7 computer to a workgroup by going to Control Panel > All Control Panel Items > System > Advanced System Settings (in the left pane) > Computer Name Tab > Change, type the Computer Name and Workgroup Name. > OK. The computer should restart.
2. First of all, go to Control Panel > All Control Panel Items > Network and Sharing Center > Change Advanced Sharing Settings and make sure you have Network Discovery, File and Printer Sharing and Public Folder Sharing all set to ‘On’ and Password Protected Sharing to ‘Off’.
3. To share a Windows 7 folder, right-click it > Properties > Sharing Tab > Advanced Sharing > Share this folder > Apply, OK > Close. Two little people should appear on the icons of the folders that are shared. An alternative way of sharing is to drag the folders you want to share to the Public folder.
4. As you don’t have Password Protected Sharing turned on, you have to change the security permissions on your folder(s) to allow Everyone access. Right-click the shared folder > Properties > Security Tab > Edit > Add and type ‘Everyone’ (not the quotes) into the box and OK. Tick the boxes next to the permissions you want to allow (e.g. Read or Write, etc.) then Apply > OK, etc. You may see some screens coming up with message 'An error occurred while applying ……..'. This is not unusual and can be ignored by clicking Continue.
BOTH
Windows firewall is normally set to allow file and printer sharing but if you have a third-party firewall make sure file and printer sharing is enabled so that each machine can talk to the other(s). Don’t disable the Windows firewall if it’s the only one you’re running.