Windows Live Messenger 2011 - 0x80048820 Logon Failure

I don't use Windows Live Messenger much, but after the install of the recent IE9 RC, I noticed that the darn thing wouldn't sign in properly.

I did the usual Google-Fu and tried stuff ranging from deleting cached contacts folders, repairing the install, removing and reinstalling, checking IE proxy settings to re-registering various DLL's all without luck.

I then tried logging (under Options > Connection > Logging) and got the following:

1aec            Messenger:              Zone_Voice (voicevideoplatformlogon.cpp:66): ERROR: [OnLogonResult called with an failure hrLogon] "" failed with 0x80048820 in .
1aec            Messenger:         Zone_LogonState CUIManager::OnLogonResult hr=[0x80048820] m_dwUILogonFlags=[2]
1aec            Messenger:                 Zone_UI CUIManager::OnLogonResult@0270CEC8: enter
1aec            Messenger:         Zone_LogonState CSignInUIController::OnLogonError> hrError=[0x80048820]
1aec            Messenger:         Zone_LogonState CLogonErrorHandler::DisplayLogonErrorDialog> hrError=[0x80048820] s_fDisplayingLogonError=[0]

I did a bit of network tracing, and found that messenger was trying to use my work proxy. Strange for several reasons:

• I wasn't connected to my work VPN
• I didn't have any proxy settings in IE9
• Work blocks messenger, so it could never have worked like that

After a little more head scratching, I remembered using the "netsh winhttp" commands to set a proxy to try and fix some VPN proxy issues we had, and when I checked, I could still see the winhttp proxy settings set.

Entering the following command cleared the proxy, and allowed messenger to run:

• netsh winhttp reset proxy