Hi Candi Hansen,
Actually there are some other ways you can try, skipping the preview update for instance. You don’t actually need the preview version of .NET to run QuickBooks. In the settings -> win update, click pause updates for 7 days, then check for updates again. This may trigger the regular updates (non-preview) to install.
Or, you can uninstall the .NET preview manually in control Panel. Look for anything with .NET Framework Preview and remove it. Then reboot and try updating QuickBooks again.
Another way out is to run Win Update Troubleshooter
If none of the above works, which I don't hope to, QuickBooks Tool Hub is your last resort. It can fix update issues. Just download it from the official site, run it, and use the program problems or Installation Issues section.
If you think this piece of advice is useful to some extent, don't forget to accept the answer so more people would also have a chance to benefit from it too. Thank you :)
Vivian