Maybe this can Help.
Win7 when configured on peer-to-peer Network has three types of Sharing configurations.
= Works only between Win 7 computers. This type of configuration makes it very easy to Entry Level Users to start Network sharing.
= Basically similar to the previous methods of sharing that let you control what, how, and to whom folders would be shared with.
= Public Network (like Internet cafe) to reduce security risks.
For best results log to each computer's System Screen and set all the computers to be on a Network with the same name while each computer has its own unique name.
Make sure that the Software Firewall on each computer allows free local traffic. If you use 3rd party Firewall On, Vista/XP Native Firewall should be Off, and the active Firewall has to adjusted to your Network IP numbers on what is some time called the Trusted Zone (consult your 3rd Party Firewall instructions
General example, http://www.ezlan.net/faq#trusted
If your network is comprised of Win 7 only and you want a simple Network, use this.
If the HomeGroup Network keeps given you "Hard time", and you are willing to spend some time on learning and configuring the Network, switch all the computers to the more flexible Work Network.
In the Network Center, clicking on the Network type opens the window to the right.
Choose your type of Network. Notice the check mark at the bottom, and check/uncheck it according to your needs.
Win 7 - http://windows.microsoft.com/en-us/windows7/Networking-home-computers-running-different-versions-of-Windows
Win 7 Work Network specific folder sharing - http://www.onecomputerguy.com/windows7/windows7_sharing.htm
When finished with the setting of the system it is advisable to Reboot all the hardware including the Router and all computers involved.
If you have Permission and Security issues, check the following settings.
Point to the a Folder that meant to to be share. Right click and choose properties.
In the properties
Click on the Security tab shown in the pic bellow to the right) and check that the users and their permission (shown in the pic bellow center and left) are correctly configured. Then do the same to the Permission tab.
This screen shot is from Win 7, Vista's menus are similar.
In both the Security panel, and the Permission panel you have to highlight each User/Group and examine that the Permission Controls are checked correctly.
When everything is OK, Reboot the Network (Router, and computer).
. The Groups and Users shown in the screen-shoot are just an example. Your list will look the way your system is configured.
. You have to establish specific users. Everyone
means all of the users that already have an account and been established as users. It does not mean Everyone
that feel that they would like to login.
Some of the processes described above are done Not for Windows sake but to compensate for different Routers and the way their firmware works and stores the info about the computers that are Networked.