No. They just need to be on the same subnet and belong to the same Workgroup.
However, I've found that file sharing seems to work 'easier' if they are on the same Homegroup.
Actually if One Opt to use IPv4 WorkGroup (as oppose to HomeGroup), it is better to switch Off HomeGroup and Uncheck IPv6 from the Network properties.
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Permission and Security, 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.
http://www.ezlan.net/Win7/Permission-Security.jpg
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).
* Note . The Groups and Users shown in the screen-shoot are just an example. Your list will look the way your system is configured.
**Note . All users that are allowed to share need to have account onall the computers that they are allowed to connect to.
Everyone is an account, it means a group of all of the users that already have an account and been established as users. It is available to avoid the need of configuring permission to each on its own, it does not mean
Everyone that feel that they would like to login.
