Stuck on Git on Windows: Can't checkout, can't stash, can't commit

Question

I'm stuck... If I do git stash I get:

Fatal: Unable to create /index.lock: File exists. If no other git process is currently running, this probably means a git process crashed in this repository earlier. Make sure no other git process is running and remove the file manually to continue.

After manually removing index.lock, I get:

Rename from .git/index.lock to .git/index failed. Should I try again? (y/n)

git checkout master:

 Rename from .git/index.lock to .git/index failed. Should I try again? (y/n)

git commit via GitHub:

Unable to create a new commit

What can I do?

Answer 1

Solved it using the universal fix for all software problems: restarted the computer.