Double-click the bk_demo_copy folder.

Hmm. Some files with big green buttons on them and a subdirectory. Ok, so the files with the big green buttons on them are files that are under BitKeeper control. The green icon with a minus sign is showing us that these files are checked out in read-only mode. Let's go look in that e2fsck subdirectory and see what's in there.

Double-click the e2fsck folder.

You can see that the files in this directory are also marked with the green minus icon, telling us they are marked read-only, so the first thing we want to do is mark the files for editing so that we can start making some changes.

Right-click on the white background of your Explorer window. Click BK Edit Files...

If no files are selected, this action means to checkout all of the files in the current directory for editing. Now our directory should look like this:

Ok! The green check marks say that these files can be edited, so we're ready to make some code changes! If you want to learn more about why we need to checkout files for editing, see the note on checkout modes for extra credit.