In the past few days my Windows Live Messenger just won’t start up, every time i try to sign in, it always give me this.

I’ve tried uninstall and reinstall with the latest set up download from the official Microsoft Website, and no luck.
So I did some Googling…. find that Microsoft have a Live Solution Center Web site so I read a bit, in my case it probably changed my profile picture earlier and for some reason the UI could not start up, and I did tried to uninstall it completely and reinstall it and no luck, I think it is some registry entry still there.
Try CClean to clean up the registry an nope, the problem still persist. So I thought why not go for the new Beta version of Windows Live Essentials.
When I try to install, the beta version is incompatible with the Live mesh installed in my machine, so I use some uninstaller tool to remove it, and install again, and the Live Essentials install still complaining about my other account on the current machine still have the mesh installed, so I login my other user account uninstall it and it still would not let me install the Beta version, so I did some research again and find out how to remove live mesh completely.
First you need the live mesh installer the exe file, if you don’t have it, just go to the live mesh site to download it again.
Use the command prompt navigate to the file just download and use the /uninstall switch with the LiveMesh.exe file, you can use -help to see more switch. [LiveMesh.exe /uninstall]
If you like me uninstall the live mesh earlier, just install it again and the use the command to uninstall it. After the un-installation, you still need to edit the registry for the Windows Live Essentials Beta installer to pass the per installation check
The registry KEYS follow:
HKEY_CURRENT_USERSoftwareMicrosoftInstallerProducts9D1E4BCD781B45B479E1418784C5A935
HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionInstallerUserData
<ACCOUNTSID>Products9D1E4BCD781B45B479E1418784C5A935
After remove those 2 entries, restart the computer, and the installer finally could start the installation.

and the new Windows Live Messenger looks like this

Windows Live Messenger Beta can connect to your social network account e.g. Facebook, MySpace etc…
Finally i am back on line