Format WD hard drive, does not work?

The question title now gives only a little information, but I have no specific question xD

I have a WD hard drive here, which I had connected to my receiver. As far as I know, there were only recorded films on the hard disk.

Now I wanted to connect the hard drive to my PS4, for which you have to format the WD first. So I plug it into my PC to secure the films and then format them. In Explorer, I then only find loud folders that are actually on my PC, but not on the hard drive (e.g. Users → Documents, Downloads, etc.). But without files, only the folders (except my last downloads on the PC were on the hard drive?!:, D) Everything except my films. If I press format, the following message appears: Formatting not possible because the Windows version is installed on the hard drive, without which the PC does not run. I'm confused and ask for help.

PS: The films are definitely on the hard drive (the PC itself shows that 80 GB are used)

Proceed as follows:

Open Explorer → Connect hard disk → Select the hard disk that was added in the list on the left. Right click on this and then format it.

Did you read the text at all?

Did you also choose the WD hard drive? Sounds like you want to format the internal hard drive from your PC and logically you can't.

Oh yes, my mistake… But then the PC does not read the hard drive at all… There's a sound like the normal USB stick, but in the Explorer it shows me The hard drive does not show (That explains a lot, was really confused haha)

Look in the disk management if the disk can be found there. Possibly. You need to assign a drive letter.

Thanks, I made it, the option is there, but I can't click it. So I can't assign a letter

Yes, and it looks like you chose the wrong hard drive