I just upgraded to Git 1.8.0.1 for Windows, from my previous version 1.7.9.mysysgit.0. I downloaded the new version from the Git site and installed through the normal Git in
If you look at the most recent update on Git's website in the "git via git" section you will see an option to update your older version.
Here is the command that git has on their site:
git clone https://github.com/git/git
It worked for my version of git which was a 2.13.0.windows.1.
2.13.0.windows.1