My screen always stays black for about 15-20 seconds between the display of the mainboard / BIOS and the Windows 10 home screen when booting. That would be understandable with an older PC with an HDD, but mine has a super fast Samsung m.2 ssd, 16 GB 3200Mhz RAM and 6 cores at 4 Ghz. So why does my laptop start with 2400Mhz Ram and only 2Ghz twice as fast? (With "Autostart" I only activated Discord and Steam, but that didn't help either.)
There's a wide range of options. I think installed programs are unlikely, but you can check in the task manager under the Autostart tab whether something has a major impact that you do not expect.
More likely, however, are faulty drivers or (my favorite) faulty BIOS / UEFI settings. Reinstall drivers via the corresponding pages from the manufacturers of graphics cards etc. (although Windows Update itself does a reasonable job here).
You can change the UEFI settings via Settings (Win key then cogwheel) → Update and Security → Recovery → Advanced Start. Then the research starts again and you get a new menu. There should be something like a UEFI shell (I haven't tried it myself because I don't want to restart the computer ;-)). This leads you to the settings of the mainboard. That looks different depending on the manufacturer. You should pay special attention to the boot sequence (the m.2 should be the first). Fastboot would also be interesting. It can be worthwhile to deactivate it.
