Use the local security settings to force NTLMv2
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Overview
If the NTLM authentication setting on your Windows computer is not set to NTLMv2, your computer may repeatedly prompt you for your IU username and passphrase when you attempt to access your IU Exchange account via Outlook (or any other desktop email client).
Windows 8.x and later and Windows Server use NTLMv2 authentication by default, but in rare instances, this setting may become incorrect, even if the NTLM setting was previously correct.
You only need to use one of the following methods. Using the Local Security Policy console is easier, but not all versions of Windows include the secpol.msc
application necessary to use this method. It is usually found on business-class versions of Windows (for example, Enterprise and Ultimate). The registry option will work on all versions of Windows.
Use the Local Security Policy console
To use the local security settings to force Windows to use NTLMv2:
- Open the Local Security Policy console, using one of the following methods:
- From the Control Panel: Navigate to the Control Panel. Double-click , and then .
- Via search: Search for the
secpol.msc
application and launch it. To do so:- In Windows 11, Windows 10 or Windows Server 2016, use the search function from the Taskbar.
- In Windows 8.x or Windows Server 2012, swipe down from the upper right corner, select
secpol.msc
, and pressEnter
.
, enter
The Local Security Policy console will appear.
- Find "Network Security: LAN Manager authentication level", which is located in Security Settings, Local Policies, Security Options.
- Set the LAN Manager authentication level to .
Edit the registry (advanced method)
If the secpol.msc
control described in the instructions above is missing, you can make this change directly in the registry.
- In Windows 8.x and later, initiate a search.
- Enter
regedt32
. Click or . - Double-click , then , , , and finally .
- In the right pane, double-click the value.
- In the "Data" field of the DWORD Editor window, enter
5
. Click . - In the menu, select .
- Restart your system for the registry changes to take effect.
This is document atcb in the Knowledge Base.
Last modified on 2023-10-24 16:56:53.