What's on my PC?

My browser of choice. Here I set up FFSync and Privacy Badger. Goes on your PC first, because MS Edge is just there for downloading a decent browser.

KeePass was my password manager for years, and KeePassXC is a good reimplementation of it. I'm mostly choosing this one because I also use it on linux. Otherwise I'd probably use the original KeePass on windows.
This goes on the machine next, because it holds not only passwords but also software keys! Yes, the rest of the list is mostly FLOSS software, so this is much less of an issue nowadays.

The desktop sync client for nextcloud, which is where many of my files are stored.

Quickly starting image viewer with basic editing functionality (resize, crop, etc.) This has replaced IrfanView for me, because it is open source and also because of its support for SVG and transparency.

Simple and quick PDF viewer. Especially useful is navigating across files with Ctrl+Shift+Left (or right). Also handles ebooks, but I don't use it much for that.

Handles pretty much any video and audio format that you throw at it.

When I'm working on a project. This is almost VS Code, but only the MIT parts. A short while ago this would have been atom editor, but now I'm using this as well. Like everyone else.

Opens quickly. This is my default handler for all text-based file formats (so it could also go in the "looking at stuff quickly" category). It highlights all formats that I usuallly encounter. Has a few neat tricks to work with text files and handles very large files as well.

I don't really know why I keep it around, but I simply like it.

An open source note taking and to-do application with synchronisation capabilities.

Nice GUI diff tool that lets you do a 2- or 3-way-comparison graphically.

Tabbed terminal for windows, also includes the usual unix tools (ls, find and so on) which is nice to have. Defaults could be better, but you can configure it quite extensively.

This is fairly new on this list, but it certainly beats pure

Windows now includes OpenSSH by default, but PuTTY can also connect to serial ports.

How else would you keep track of your projects?

HANDLE ALL THE COMPRESSED FILE FORMATS. (could also go in "looking at stuff QUICKLY")

This backs up all my files to a different drive. It can do much more, but that's all I need.

If I ever need to move files to or from a server via FTP or SFTP, FileZilla is usually the easiest way for me.

Find out where all your disk space went.

I have set Thunderbird up in a way that I like. I think it's good software. It's not fancy, but it works very well for me.