Is there an alternative for explorer.exe's start menu function (& alt-tab) that doesn't rely on explorer.exe? I'm getting 0xc0000409, so can't use it

I don't know why every single supposed alternative (StartAllBack, start11 etc) uses explorer.exe itself, which makes me unable to truly replace it... otherwise, any help with 0xc0000409? On MS' site there's only the usual templates... at times keeps crashing and restarting every five mins...

I've tried this Cairo shell, but it doesn't replace tab-alt, there's something wrong with clicking minimize etc. and when I tried to access settings it claims it might not exist or it has no access to it...