windows – Removing Linux partitions from dual boot machine

I have a Dell Latitude 3560 laptop that was, of course, delivered with Windows 10. When it was received, I shrunk the Windows partition down to 60GB and installed Fedora 28. The machine boots into Fedora properly and can boot Windows by selecting it from the grub screen.

I don’t get much use out of the machine (I have others) and want to remove all the Linux partitions and re-grow the Windows partition, so somebody else can use it.

I don’t have Windows install media, since the system came pre-installed.

I’m afraid that if I delete the Linux partitions, I’ll have no MBR and it won’t boot at all.

How can I preserve a boot record so the machine will continue to boot Windows 10?