How can I disable the Windows Credential Manager?

It turns out that the Credential Manager that was causing the problems was part of the "HP ProtectTools Security Manager Suite". Once I uninstalled that, along with all the other HP cruft that was pre-installed on this OEM box, the login problems disappeared.

You could possibly find the answer to the problem which produced this question...
How to disable the Windows Credential Manager,
'Run as' Admin:
Menu -> Accessories -> Administrator Tools -> Services (or Component Services then Services),
-> Services( Local )
-> highlight Credential Manager -> Right-Click on, select properties, -> General tab,
-> 'Startup type' in drop-down tab, ->select disabled.
Click 'Apply' then OK.

Backup by Exporting,
Services can be viewed in extended or standard - change view at the bottom.
Hope this helps.