Windows 7 can't access Share in a workgroup

Start – run – secpol.msc

Then…

Browse to "Local Policies" -> "Security Options". Now look for the entry "Network Security: LAN Manager authentication level" and open it. Click on the dropdown menu and select "Send LM & NTLM - use NTLMv2 session security if negotiated". Apply the settings

Please check related policies.

1. Enter “gpedit.msc” in the Start Search box.

2. Open “Computer Configuration”/Windows Settings/Security Settings/Local Policies/Security Settings.

3. In the right pane, enable the following policies:

Network access: Allow anonymous SID/name translation

Network access: Let Everyone permissions apply to anonymous users

Also please disable the following policies.

Network access: Restrict anonymous access to Named Pipes and Shares

Network access: Do not allow anonymous enumeration of SAM accounts

Network access: Do not allow anonymous enumeration of SAM accounts and shares