Found this on a forum I regularly visit:

Microsoft stopped supporting the ‘http://login:password@www.domain.com’ adressing format in IE with the windows update released at february 2. To re-enable this:

1. Create a txt file and put the code shown below inside of it then it rename to passfix.reg 2. Find the saved file and double click on it When asked if you want to add the file to the registry, answer YES

Code: REGEDIT4 [HKEY_LOCAL_MACHINESOFTWAREMicrosoftInternet ExplorerMainFeatureControl] [HKEY_LOCAL_MACHINESOFTWAREMicrosoftInternet ExplorerMainFeatureControlFEATURE_HTTP_USERNAME_PASSWORD_DISABLE] “iexplore.exe”=dword:00000000 “explorer.exe”=dword:00000000

Doing this will allow you to visit this site using the “leet” url http://m@rkus.nl/ :p