https://serverfault.com/questions/51635/how-can-an-unauthenticated-user-access-a-windows-share
Summary of steps:
Adding
Everyone
,Guest
andANONYMOUS LOGON
to the permissions of the share. Open the Group Policy Editor (e.g. by running gpedit.msc) Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options
- Accounts: Guest account status: Enabled
- Network access: Let Everyone permissions apply to anonymous users: Enabled
- Network access: Restrict anonymous access to Named Pipes and Shares: Disabled
- Network access: Shares that can be accessed anonymously: YOUR_SHARE_NAME