Can I switch to Linux without backing up my files first?

If the files matter and there’s no backup, I’d hold off on replacing Windows. An installer can erase the wrong partition, and partition changes can fail. There isn’t a migration tool that makes an unbacked-up drive safe.

Wait until you can borrow or get enough storage, or back up the irreplaceable files to a trusted cloud service if your connection and available space allow it. Games and programs can usually be reinstalled, so prioritize documents, projects, photos, and saves.

You can try Linux without installing it by booting a live USB, as long as you choose the option to try it and don’t start the installer. That lets you check hardware and get a feel for the system, but it is not a backup and won’t make replacing Windows risk-free.

Leaving Windows installed and adding Linux alongside it may let you access files on the Windows partition, but that still leaves everything on one drive. A second partition is not a backup if the drive fails or an install goes wrong.

The 16 GB stick won’t hold anything close to 650 GB, so treat it as a way to make installation media, not as your backup plan. If buying a drive isn’t possible right now, see whether you can borrow storage or use cloud space for the smaller, most valuable files. Check that the copies open before you change partitions.

Don’t rely on shrinking Windows and making a separate data partition as a workaround. It might work, but both partitions would still be on the same physical drive, and a mistake or drive failure could take out both.