Windows 2025 printer share not working

Question

I setup a Windows 2025 Printserver for substituting my old Windows 2016 Printserver. After installing and sharing the Printers I cannot access the new shares as of "bad username or password".

I am trying to access the new Printserver from FileExplorer with Entering \NewPrintserver using the same domain adminstrator account

• From a Windows 2016 DomainController: access
• From a Windows 2016 machine: access
• From a Windows 2025 DomainController: access
• From a Windows 2025 machine: no access

Any suggestions ?

Best regards
Jens

Answer 1

Hello Harry,

thank you for quick response. I changed LAN Manager authentication level to “Send NTLMv2 response only" via GPO on all machines - unfortunately without success.

(HKLM\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters\RequireSecuritySignature) does not exist on the client machine but (HKLM\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters\EnableSecuritySignature) set to 1.

Any further Suggestions ?

Best regards
Jens

Answer 2

Hello Jens,

This is expected behavior due to hardened authentication defaults in Windows Server 2025. By default, Windows 2025 clients enforce NTLMv2 only and refuse LM/NTLMv1, which can cause “bad username or password” errors when connecting to shares if the server or domain trust is still negotiating weaker protocols. You should verify the local security policy on the 2025 client under Security Settings > Local Policies > Security Options > Network security: LAN Manager authentication level and ensure it is set to “Send NTLMv2 response only.” Also confirm that Kerberos is available and SMB signing settings match between client and server (HKLM\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters\RequireSecuritySignature). If your environment still relies on NTLMv1, temporarily lowering the policy will restore access, but the supported and secure fix is to align all systems to NTLMv2 or Kerberos. This explains why 2016 machines connect fine while 2025 clients fail.

Hope it helps.

Harry.