I have had this problem twice now. Once earlier in the year. I followed ALL suggestions. NOTHING worked. I had to format the HDD and reload the original OS (Windows 7 upgraded to professional). Then went through the agony of Microsoft auto installing 200+ "updates", that took over 2 weeks to install properly BEFORE the computer would settle down and work right. Damn them!
Everything has worked fine for the past 6 months or so. Then today the problem occured again. But this time I went further. NOT only was I not able to launch Windows live messenger, I found I could not update Windows 7, NOR could I update Windows Security Essentials either. Each gave me similar messages. (Yet I had NO problem in launching Yahoo Messenger, etc).
It seemed to affect ONLY Microsoft programs.
After many hours of fruitless trials and errors and trying EVERY thing I could think of, my prayers were answered. I felt the notion to go into Control panel and see if there was ANY program that was insalled in the last several days. And Voila'. There was indeed a new program loaded into my PC that I had NOTHING to do with. It was installed on the 7th, the day before yesterday!
It is titled "Intel Matrix Storage Console". I uninstalled it and ALL worked instantly fine.
How this program got installed on my computer I have NOT a clue; because I am very leery and careful about ANY program being installed in my PC, because of past nightmares. In any case, removing it solved the problem.
Note: Running a scan using Windows Security Essential picked up NO problems. So they got a problem and don' know it. Oh well. It apparently has something to do with their incessant "security updates" I imagine; and would explain why it ONLY affects THEIR programs. DAMN them!
Hope this helps someone(s). And praise Jesus,