Something else that's just popped into my head. Another reason why USB sticks aren't often recommended as recovery media...... the OS changes with new updates quite frequently. When downloaded from M$ themselves, you are guaranteed to have the latest stable version of the OS with all the updates in it. Installing from a USB you have had for a number of months/years would be ill advised for anything other than an emergency situation. A fresh download from M$ would always be recommended, even on a system that's mere weeks old, as you have no idea how old or which version of OS you are receiving.