Something I only saw mentioned in a somewhat snarky comment in this thread (apologies if I missed it elsewhere) is that Windows has the option to do a full system image backup.
If you have an external hdd or a nas, from the Windows Backup applet in control panel (not settings) you can create a system image that will contain a full backup of your C: drive and, optionally other drives in your system. You can then restore that backup from the recovery options in your windows install media.
For the windows install media, I’d recommend using the windows media creation tool to create a usb installer on a separate usb key from your Linux installer and then setting it aside just in case. Trying to create windows install media from within Linux is, while not impossible, difficult.
Obviously, you should do all of this before committing to installing Linux to disk. Most Linux install media also functions as a live Linux environment from which you can try things out and see if things will work for you.