If you plan on using Custom Themes on Windows 11 or even Windows 10, the first thing you need to get used to is them breaking almost every time Windows updates. Basically, every single time Windows updates, it resets a portion of the system, which breaks custom themes. Some updates break things worse than others, so follow along as this guide shows you how to fix broken themes after Windows updates.

Takeaways:

  1. Do custom Windows 11 themes always break after Windows Updates?
  2. Is there a way to stop Windows 11 updates from breaking custom themes?

How to Fix Custom Windows 11 Themes After Windows Updates Break Them

A custom theme that worked perfectly one day can suddenly revert back to the default Windows appearance after a major update. Most of the time, some parts of the theme still work while others vanish. While icons usually stick around, window styles and colour schemes in File Explorer typically reset.

The good news is that you won't have to do everything from scratch since most of the files used are still in their required position. It's the linkages and tweaks that break.

So everything you moved into C:\Windows\Resources\Themes will usually remain exactly where they are.

Reinstall UltraUXThemePatcher

  • The first step is to reinstall UltraUXThemePatcher.
  • Download the latest version of the tool and install it again. This restores the custom theme support that Windows updates may have removed.
  • After installation is complete, restart your computer.
  • Once Windows has restarted, check if your theme is working again. If it loads correctly, you are finished. However, if some parts are still missing, continue with the remaining steps.

Normally, once you reinstall it, you can just go to Personalise and turn the theme back on. If this doesn't work, you'll need to reinstall the other stuff too.

Reinstall custom icon packs

Windows updates can also break custom icons installed through 7TSP. Your icon pack files should still be present inside your theme folder. You do not need to copy them back into the Windows themes directory.

  • Instead, you simply need to reinstall the icon patch.
  • Open 7TSP GUI again and load the same icon pack you used previously. If necessary, rename the file so it ends with: .7z
  • Then open 7TSP GUI, select Add a Custom Pack, choose the icon pack, and start the patching process.
  • Once completed, restart Windows.

Reinstall Start menu customisation tools (Not Very Common)

Some Windows 11 themes include Start menu modifications through programs such as StartAllBack. If your Start menu has returned to the default Windows 11 layout after an update, you will need to reinstall StartAllBack and configure it again. The exact settings will depend on the theme you are using, but most theme packs include instructions or configuration files that help restore the intended appearance.

From my experience, if you are using StartAllBack, you don't generally need to clean install it to get themes working again. It seems to be fairly safe after updates. Though the big 26H2 style updates might cause problems, so keep an eye on them.

Do you need to move your theme files again?

No. At least not from any of the updates I have experienced so far. This is one of the most important things to understand when repairing a broken custom theme. You do not need to extract the theme again or copy the files back into:

C:\Windows\Resources\Themes

Those files are not usually the problem. Windows updates typically break the supporting patches and customisation software rather than deleting the theme itself. The repair process is simply reinstalling the individual components that allow Windows to use those files. Once you have installed the tools, you can just reapply the theme.