A better option is to perform a clean install rather than an in-place upgrade, because the end result will be a fresh operating system that isn't bogged down with old system files, unnecessary Registry entries and incorrect drivers.Once the installation is complete, you will need to spend some time reinstalling all your programs and copying over personal data and settings, but it's worth the extra effort because it means Windows will run faster and be less likely to crash once you've finished setting up everything.
It doesn't matter if you subsequently rolled back your PC to Windows 7 or 8.1, or if you wiped or formatted your hard drive – you'll still be able to install and use Windows 10 for free on that device.
If you're planning a clean install, you will need your Windows key, which you can find by running Nir Soft's Produ Key in Windows.
It can also create a Windows To Go drive which will let you install and run Windows 10 directly from the memory stick, turning it into a portable PC that you can use on your travels.
You will need a very fast flash drive for this option, however.
The exact method for downloading and installing USB 3 chipset drivers varies depending on the computer/motherboard manufacturer and USB 3 chipset manufacturer, but the general steps below outline the process for most systems. The computer/motherboard manufacturer and model will be listed under "Manufacturer" and "Model" respectively. Go to the computer/motherboard manufacturer's website and locate your computer/motherboard model.