@gmckay60 if your laptop has a USB port you should be able to save your brushes and any other important data to a USB stick.
Open Krita and go to settings - manage resources. Near the bottom of that panel you’ll see “open resource folder.” Click that and you should see a folder “paintoppresets.” In that folder you should see your brush files with the names you gave them. All you need to do is copy those brush files to the USB stick. Make sure you don’t lose the “_” character in the file names.
When you’ve reinstalled W10 and Krita. Use Krita’s resource manager to open the resource folder. Open “paintoppresets” and copy your brushes from the USB stick to “paintoppresets.” Restart Krita and your brushes should be in the “all” group.