This will work on vista (Make sure you read the whole thing).
I stumbled across this fix via a web search in the Live Messenger Blog about a different error code. It worked for me on Windows Vista.
1.) Close Messenger. Go into Task Manager and ensure that the “msnmsgr.exe” process is not there. If it is, kill the process.
2.) Navigate to C:\Users\\AppData\Local\Microsoft\Windows Live Contacts and delete the entire contents of the folder.
3.) Restart Windows Live Messenger. Voila!
There is another issue I found where the standalone installer for Messenger fails with a message like “could not open key…”. One fix for this is to navigate to the C:\Program Files\Windows Live\Messenger folder and DELETE the msnmsgr.exe executable if it is there.
For solution in Windows XP
1. Go to Start Search and search for "contacts.edb" on your primary folder.
2. You will probably come to "C:\Documents and Settings\[UserName]
3. Delete every thing.
4. Try to connect.
5. If you can't connect. On the right bottom of your pc, double click on the clock and make sure your Date "Month" "Year" "Time" is correct. (This was my problem). Fix it
6. Try again.
7. Ta..da... there you go. Hopefully this helps.
