As a Windows user I recently struggled to figure out how to make TortoiseGit push my local code to a remote Google Code repository. Google Code gave me a password to use but the client never asked me for it. If you are having the same problem here's how to fix it!
The short answer is to add the password Google gives you to the URL using something like this https://name:password@path_to_repo/
Create your project on Google Code or find the Git hosted project you want to commit to. Go to the Source tab and grab the clone URL (you have to be signed in to get this). Navigate to your local folder you want to hold the repository and clone it through TortoiseGit the normal way.
Once you have cloned it navigate to the directory, right-click and choose TortoiseGit -> Settings
Select Git on the left hand side.
Select Edit local .git/config
This opens up a config file. Look for the URL line that looks something like this
url = https://firstname.lastname@example.org/p/your-project
Get your GoogleCode password from here and paste it in so the line looks something like
url = https://username:email@example.com/p/your-project
If all goes well when you Push you should see something like this!