How do you boot a laptop with a USB stick?

I can only enter the BIOS on my old laptop, it is version F. 16. I have created a FAT32 USB stick with the Windows 10 ISO file. I plugged it in and restarted the laptop. Nothing happens, although it somehow worked the day before yesterday. Key F10 = BIOS, F12 = Boot From LAN, esc = Boot Order.

I created a FAT32 USB stick with the Windows 10 ISO file.

Did you actually make the stick bootable, i.e. With a program such as Rufus?
Make sure that the USB stick is directly in the PC, not via such a USB splitter or anything else… In addition, the boot sequence must of course be changed in the BIOS so that the USB stick is at the top. In addition, Fastboot must be deactivated, this can also be done via the normal Windows settings. And then Secure-Boot must be deactivated in the BIOS, this is to prevent e.g. Malware from starting in front of the system, but often also prevents booting from a USB stick…

Did you just drag the ISO onto the stick using File Explorer, or did you make it bootable using Rufus?

You also have to pull the USB stick first in the boot sequence in the BIOS.

You have to tell the BIOS to boot from the stick. This can be done either via the boot menu (F-keys when booting), or via the BIOS by changing the boot sequence.

The problem is, I can only put USB hard drive first. There's nothing else with USB.

Is there a USB hard drive? If not, the stick is meant.

The question remains (see above):

Did you just drag the ISO onto the stick using File Explorer, or did you make it bootable using Rufus?

The Windows 10 stick is best created with the Media Creation Tool: https://www.microsoft.com/...ndows10%20

This tool packs Windows 10 and the latest updates onto the stick and makes it bootable. You don't have to download a Windows 10 ISO separately.