I installed a new hard drive. I created a USB flash stick with Windows 10 installed on the flash drive. The screen says OPERATING SYSTEM NOT FOUND.
I put in my flash drive and it flashes light for three seconds then nothing happens. I push the power off button and nothing happens.
Maybe I need to disconnect the battery but who knows what the screen will say and I'm wondering how to install Windows 10 if I get the same message after disconnecting the battery.

Edit: Reconnecting the ribbon wires is like vascular surgery. They keep coming undone and I found the ribbon wire to my power button unplugged.
I'm about to throw in the towel. It's perhaps an 8 year laptop that says Windows 7 on it; off course with a new hard drive I have no installation system. Maybe without a license for Windows 10 I should try and install Windows 7 because I read the motherboard has information that the laptop has a Windows 7 license?

Hold the power button. It will turn off after 5-10 seconds max.

You need to boot to the USB drive.

Bios/Boot Menu Keys by brand

I don't remember if UEFI was around 7 years ago, but you might have to format your USB drive for BIOS instead. I can't remember if the windows media creation tool has that as an option.