Use Open Shell to get the Windows 7 start menu and you can also replace the default start button with the good old blue Windows orb (attached). See also my post (link below) how to make Classic Explorer Bar from Open Shell work again after upgrading to Windows 11 25H2 build 8117 or higher. Then you can also replace the wallpaper with the standard Windows 7 wallpaper (attached). If you prefer any other wallpaper, then you can copy it from another computer or virtual machine running Windows 7. They all are in folder
C:\Windows\Web\Wallpaper To get some of the good old desktop gadgets (not modern widgets) you need 8gadgetpack version 37.0.0 Don't download any newer version, they removed support for old Vista/7 gadgets, very stupid of them! To get Windows 7 system icons you must first extract them from the respective Windows 7 system files with Customizer God and then import them in the equivalent Windows 11 system files with the same software. These cannot be modified directly, you must first copy them to another folder where you have full access, modify them, and then take ownership of the original files and containing folder and grant full access in order to replace them. If you need any details, tell me or you can see my relevant posts in Personalization section. You can even find a patched version of Windows Media Center for Windows 8.1 to install it in Windows 11, if you want to use it. Also thanks to Winaero we have classic Windows games (Solitaire, Mahjong Titans), classic calculator (the modern app is ugly), old Microsoft Paint and many more.
System files in Windows 7/8/8.1 and old versions of Windows 10 (up to v1809):
C:\Windows\System32\batmeter.dll for the power and battery icons
C:\Windows\System32\imageres.dll for the folder icons and most other system icons
C:\Windows\System32\pnidui.dll for the network icons
C:\Windows\System32\SndVolSSO.dll for the sound icons
C:\Windows\System32\stobject.dll for the USB safe removal icon
System files in newer Windows 10 and Windows 11:
C:\Windows\SystemResources\batmeter.dll.mun for the power and battery icons
C:\Windows\SystemResources\imageres.dll.mun folder icons and most other system icons
C:\Windows\System32\pnidui.dll for the network icons (only Windows 10 and Windows 11 21H1, 22H2 and 23H2)
C:\Windows\SystemResources\SndVolSSO.dll.mun for the sound icons
C:\Windows\SystemResources\stobject.dll.mun for the USB safe removal icon
All
.dll.mun files CANNOT be modified directly or you get an error and mess your system icons. Also to see your custom power/network/sound icons you must first ungroup them with Explorer Patcher. In 24H2 and 25H2 Microsoft removed the system file containing the network icons, so Explorer Patcher provides its own copy:
C:\Program Files\Explorer Patcher\pnidui.dll which can be modified directly. To see the custom network icons you must set taskbar to Windows 10 style in Explorer Patcher settings.
This project aims to enhance the working environment on Windows - valinet/ExplorerPatcher
github.com
What's Changed Fix search auto-selecting wrong item before programs finish loading by @nnyj in #2451 Update font face names in Japanese localization by @coolvitto in #2409 Fix open/save file dialo...
github.com
I think you misunderstood. Open Shell classic start button and start menu are still working fine. There is one component, a "legacy" toolbar called Classic Explorer Bar which shows cut/copy/paste and other icons (can be customized) top left of a File Explorer window. See my screenshot in post...
www.elevenforum.com
CustomizerGod will allow you to easily customize the appearance of pretty much any part of Windows making your experience so much more personal....
www.majorgeeks.com
Download Windows 7 Games for Windows 11, Windows 10, and Windows 8. Classic card games from Windows 7.
win7games.com
Here are some screenshots, I have even changed the default ugly user account picture with one from Windows 7:

I even replaced the keyboard layout language text (ENG/ΕΛ) with the respective country flag and the flat Windows 10/11 logo with the orb in the About Windows.