Internet Explorer::cannot post data to a non-NTLM-authenticated Web site

KB251404

SYMPTOMS
You cannot post any data to non-NTLM authenticated Web sites.

CAUSE
This issue can occur after you visit an NTLM authenticated folder.

RESOLUTION
add a value to the following registry key:
HKEY_CURRENT_USER/Software/Microsoft/Windows/CurrentVersion/Internet Settings/
Add the following registry value:
Value Name: DisableNTLMPreAuth
Data Type: REG_DWORD
Value: 1

Also, turn off Enable Integrated Windows Authentication in Internet Explorer.
1. Start Internet Explorer.
2. Click Tools, click Internet Options, and then click the Advanced tab.
3. Under Security, click to de-select Enable Integrated Windows Authentication (requires restart), and then click Apply.
4. Close Internet Explorer.

To resolve this issue from the server side, configure the Web site to use either of the following authentication methods:
• Configure the Web site to permit anonymous access only.
• Configure the Web site to permit both anonymous access and NLTM authentication (Integrated Windows authentication).