Question Dual-boot problems with Win7/10

Apr 1, 2022
Hi everyone,
As the title says, I got a problem with my dual-boot. I had Windows 7 (6.1.7601) installed and wanted Windows 10 (10.0.19043) in addition, so I bought a new SSD and installed 10 on it.
Now to the problem: if I boot the system from the Windows 7 SSD, it starts 7 without a hitch (not really but more to that later *). If I boot from the Windows Manager Boot, I can choose 10, which starts ok. But if I choose 7, I get a black screen that says:
Data: \Windows\system32\winload.efi
Status: 0xc0000428
Info: The digital signature of the data could not be verified

To my second problem (*), when I turn on my pc, it wants to disk check all of my harddrives. I did let it run the check and it said that everything was good. But each time I start the pc it still wants to run a disk check.

Any idea on how I could fix those problems would be much appreciated!
Please let me know if you need more details.