Windows 10 boot menu grub rescue?

I had Windows 10 and Linux on my laptop.

Because I wanted to remove Linux, I deleted the Linux partition.

After a new start I got into the boot menu with: grub rescue>

How can I start Windows again?

I tried the boot repair disc on a USB stick, but it just says that no operating system was found.

You have to restore / repair the Windows boot loader, then you can do it again.