How do I get my solution folder to revert to a previous tagged commit?

[Deleted user]

I am trying to get my current solution folder to revert to exactly the state it was in some months ago. The commit I want to go back to is tagged but is not a branch.

If I double-click the tagged commit I want to go back to, SourceTree tells me I am creating a detached HEAD but says I can subsequently create a branch so I don't lose the changes I will make.  I go ahead with this and select the 'Clean' checkbox to discard all changes.

When I then go to look at my solution folder in Windows Explorer, it is a hotchpotch of the old and the new.  I do get back the folders that were in existence when I created the tagged version a few months ago but I also still have new folders that I have created since and did not exist back then.  This gives me zero confidence that I can go ahead doing a patch for the old software.

What am I doing wrong?

[minnsey]

Create a new branch from the commit you want, then from the terminal run 

>Git clean

see https://git-scm.com/docs/git-clean

This should remove any untracked files.

(As always its worth making a backup of your local repo folder before doing this ;) )