>>15071You can install Linux on an USB stick, and run it as a normal persistent operating system. Without modifying anything on the laptop. You just plug in the stick and when you boot the computer you press the button that lets you choose to boot from USB.
I recommend using a usb3 with at least 64GB. Getting a decent quality stick helps with speed and prevents data loss. You can also use an external USB SSD/hard-drive if you need more space. (tends to have more speed and less data loss, but costs more)
It's best to use a lightweight Linux distribution for that.
You also need to learn about making an USB device bootable.
There are a lot of tutorials for this on the web and youtube.