If you have SharePoint configued to use NTLM with Integrated Windows Authentication (IWA) then it can be tricky to come into your portal as someone other than yourself. There is a cool way to force SharePoint to present a login prompt to check your credentials again. This is very useful especially when you are trying to test with other accounts.
The trick is to append:
to your site collection URL. So if our URL was “http://yoursharepointsite” then the example would be:
Hope this helps, questions are welcome.