[DEPRECATED] Simple Classic Theme

i was able to open it with the command you gave me, but only after replacing the desk039.cpl with deskn.cpl.... but now it won't save my settings! (the apply button works but nothing changes)

It's not "the same":

The Windows Basic theme can only be enabled because it's the only theme that doesn't use hardware acceleration. So by disabling hardware acceleration (The DWM), one can activate this theme.

The Windows Classic theme also doesn't use hardware acceleration but is a theme implemented directly into the core of Windows. That means that by disabling themeing all together, the Windows core just straight up falls back to Windows Classic.

Windows Classic just works because all other things that need DWM can just use it. Since DWM is disabled with Windows Basic way more bugs come up because DWM is inaccessible. So for Windows Basic, a lot more patches are required to make your system even remotely "usable".

If you don't want any of that nonsense I would recommend something like this:

If you google a bit around you'll probably find something similar for Windows 10

This AHK works:

While(true)
{
WinWait, A
DllCall("dwmapi\DwmSetWindowAttribute","uint",WinExist(),"uint",2,"int*",1,"uint",4)
}

Unfortunately, it doesn't make them think DWM is disabled; it only makes them use the basic frame.

Those programs look like this with the script:

while the real DWM off (which is really unusuable in 20H1) looks like this: