Disabling Windows Loopback Check for SharePoint Server 2007

The loopback check will cause constant password prompts appear whenever using host headers in SharePoint 2007. To get around this, you can make exceptions in the Loopback Check security feature, or completely disable it. The steps on how to sort this, are below:

Dev Environments (Less Secure Method)

1. Click Start > Run > type 'regedit' > OK
2. In Registry Editor, locate and then click the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
3. Right-click Lsa, point to New, and then click DWORD Value.
4. Type 'DisableLoopbackCheck' and then press ENTER.
5. Right-click DisableLoopbackCheck, and then click Modify.
6. In the Value data box, type 1, and then click OK.
7. Quit Registry Editor, and then restart your computer.

Live Environments (More Secure Method)

1. Click Start > Run > type 'regedit' > OK
2. In Registry Editor, locate and then click the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\MSV1_0
3. Right-click MSV1_0, point to New, and then click Multi-String Value.
4. Type BackConnectionHostNames, and then press ENTER.
5. Right-click BackConnectionHostNames, and then click Modify.
6. In the Value data box, type the host name or the host names for the sites that are on the
7. local computer, and then click OK.
8. Quit Registry Editor
9. Restart the Computer

If you are doing this on SharePoint, you will need to do this on all SharePoint servers in the Farm.