Hi @bjoernrasmussen ,
You cannot simply transfer the old HDD from one PC to another one, without expecting some problems, unless both PCs were identical. In your case they’re not. One is a Dell and one is a HP.
There will be motherboard hardware driver issues as well as Windows issues.
Here’s a [https://au.pcmag.com/gallery/63308/how-to-move-your-windows-drive-to-a-new-pc|link] that may help