I’ve recently been suffering with a problem using the latest version of Windows Live Messenger (WLM/MSN) which was when I was signing in I was prompted with an error code of 8100030D, I tried the usual stuff like reinstalling WLM and reverting back to an older version of WLM with no luck. I was confident I could fix it today and managed to do it. I will try my best to explain what I did and hopefully help others. If you try these please bear in mind that I am using Vista 64bit with Service Pack 1.
Here’s what I tried and what eventually worked:
What worked for me:
- Deleting the contents of C:\Users\AppData\Local\Microsoft\Windows Live Contacts
What I tried and could possibly work for others:
- Checking the time and date of my PC to make sure it was correct.
- Disabling any Firewall
-
- Running these commands in “Run”
- regsvr32 softpub.dll
- regsvr32 wintrust.dll
- regsvr32 initpki.dll
- regsvr32 MSXML3.dll
- Telling WLM to forget your current user’s saved password
Hopefully can assist at least one person 
