I have: http://windows.github.com/
My current project has around 20k files, around 150MB (and not speaking about how slow it is and I cannot do a thing now) it doesn\'t
I REBOOTED my Windows 7 machine and tried again - IT WORKED!
I had the "Commit failed: Failed to create a new commit" and tried to delete the index or index.lock file via windows command prompt and that didn't work. I deleted it via windows explorer, that didn't work.
I tried to check credentials like another reply in this list said, but couldn't figure it out and the credentials seemed 'ok.' So - I rebooted. Viola.
I'm not sure this will help anyone, I'm not all that great w/ this stuff, but trying.