Solving access shared folder problem between Windows 7 and Windows 2003

By default Windows 7 cannot access shared folders on Windows 2003 / 2000 or vice versa because there is a difference in LAN manager authentication policy between them. To solve this problem, you can do the following steps.

1. In Windows 7:
     1.1 Click the Start button and type secpol.msc then click OK
     1.2 In Local Policies >> Security Options,  double click on Network Security: LAN Manager authentication level to open it, then select Send LM & NTLM - use NTLMv2 session security if negotiated.  Apply this setting.
     1.3 Open Control Panel >> All Control Panel Items >> Network and Sharing Center >> Advanced sharing settings, in your current network profile, choose below options:

• Turn on network discovery
• Turn on  file and print sharing
• Use user accounts and passwords to connect to other computers

     1.4 Log off or restart Windows 7

2. In Windows 2003 / 2000:
2.1 Click the Start button and type gpedit.msc then click OK
2.1 In Computer Configuration >> Windows Settings >> Security Settings >> Local Policie >> Security Options, double click on Network Security: LAN Manager authentication level to open it, then select Send LM & NTLM Responses.  Apply this setting.
2.3 In Run box, type gpupdate /force then OK to update new policy, OR restart Windows 2003

That's all. Now you can try to access your shared folders between Windows 7 and Windows 2003/2000.