Thanks for your help. I have now got a USB stick and run the tool. How do I reinstall Windows on the other laptop with it.
You'll want to boot from the USB device - that is to say start from the USB rather than the built in hard disk.
In your first post you mentioned it being a HP laptop - so I would recommend trying the F9 key as soon as you power it on press it repeatedly. Sometimes it's another key on the top row.
This should give you a menu, it will either list the USB drive as an option (normally it will say the USB make and model eg Kingston Data Traveller) or it will say choose boot device, in which case, select that option first.