If you use WLM 2011, the problem seems to be related to a corrupted component ofWindows Live UX Platform: reinstalling usually fix it, but if you have still troubles, you should:
1. Uninstall WL UX Platform by using this command in the command prompt:
MsiExec.exe /X{CE95A79E-E4FC-4FFF-8A75-29F04B942FF2}
2. Clean system registry (with CCleaner for example);
3. Reinstall WL UX Platform.
Complete informations and procedure on the **original article**.
If you use WLM 2009, the problem is related to Windows Live Communications Platform: please read**here**.
Note: You can translate these articles with the widget on the left of the page.