Is it still possible to upgrade a windows 7 pc to windows 10?

Check the drivers before you commit. On a PC that old, the manufacturer often never released Windows 10 drivers for things like the wifi card or card reader. Look up the model on their support site first. And take a full image backup of the Windows 7 drive so you can go back if it doesn't work out.

The install still works, the free part is the problem. Microsoft officially ended the Windows 7/8 key activation route in 2023, so you can't count on your old key activating 10 any more. Some people still report it working, some don't. Bigger issue is Windows 10 itself reached end of support in October 2025, so you'd be upgrading to something that's already out of security updates. If the PC is old enough to have shipped with 7, check whether it can run 11 at all - if not, it might be time to think about a replacement or a lightweight Linux distro rather than paying for a 10 licence. Back up everything first either way.