Git (TortoiseGit) - How to revert a single file to a previous revision and then undo the revert?

Question

When using Git with TortoiseGit: Does somebody know how to revert a single file(or a complete repository) to a previous revision?

For example I have a repository con

Answer 1

In TortoiseGit the answer is to right-click the project folder and click Show Log, then right-click the change you want to roll back to and click Switch/Checkout to this... . It will let you then proceed from that weird place in the commit stack, or branch in case you plan to commit and want things to stay sane.