Log on to Windows Live Messenger 2009 always failed with error 8100030d recently.

Test connection with IE proxy, it shows connection to service successfully.

Google result:

“MSN 8100030d error are usually caused when the operating system's registry contains errors or when certain system files are missing or broken; Msn 8100030d error problems are a sign of a very unhealthy system.  Msn 8100030d error are caused in one way or another by misconfigured system files”

So I tried to scan and fix Registry to fix it.

Somebody recommended RegCure, Perfect Optimizer and other tools:

http://www.fixerror365.com/tidpp-msn_8100030d_error-zz0005

But these tools are sharewares, I want to use open source or freeware. I tried Auslogics Registry Cleaner, because it is free and I am using its Auslogics Disk Defrag, which is pretty good.

Download Auslogics Registry Cleaner, install, run, basic scan, fix, 8100030d still exist.

Run Auslogics Registry Cleaner advanced scan, select all items, scan, fix, it works!