Sharing Windows 7 folder is such a pain because Microsoft has changed a lot of default setting, mainly for the security reason, I think. But that made it so difficult to share a folder on Windows 7.

Windows 7 to Windows 7

Usually, Windows 7 to Windows 7 sharing is straightforward.

Configuration

The following is the base configuration.

• All PC belongs to the same workgroup, named "WORKGROUP".
• Windows 7 Home Premium or above
• On both machines, identical user account exist.

For example, if there's an account on PC1 username=John password=happy, then on PC2, there should be matching user account (both username and password).

How to share

1. Open 'Network and Sharing Center', select 'Change advanced sharing settings' from the left panel.
2. On 'Home or Work' set the following
• Turn on network discovery
• Turn on file and printer sharing
• Turn on sharing so anyone with network access...

This may be optional.

• Use 128-bit encryption to help protect...
• Turn on password protected sharing
• Use user accounts and passwords to connect to other computers

Once the above is done, reboot the PC just in case. The PC can be accessed from other Windows 7 (and I guess Vista) at this point.

Accessing from XP

Still, you may not be able to access from XP. When you try to connect, you'll get 'PC1 is not accessible.' error. I've spent hours and hours to solve this problem, and the following is the solution.

1. On the Windows 7 machine, Open registry editor
2. Locate HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa key
3. Change the following values, it not configured this way
4. • restrictanonymous to 0
   • everyoneincludesanonymous to 1
   • Don't change the value of restrictanonymoussam (on my PC, it was 1).
5. Reboot the Windows 7 machine

After this, you can access to the PC from Windows XP machine, assuming that the same username/password exists on the XP as well.