gpu cpu upgrade psu prebuilt

Okay so this computer is terrible, it can barely run games and i really want to upgrade it. What can i upgrade to dramatically improve performance? Or can i even upgrade. Here is the computer: https://www.svp.co.uk/acer-aspire-tc-280-desktop-pc-amd-a10-7800-apu-8gb-ram-2tb-hdd-windows-10.html...