I grew up poor and in the Caribbean. Every Saturday morning some junker would get pushed into this covered porch (just a roof, no walls) and the neighborhood gear heads would decend opon it like a swarm of Stargate SG-1 replicators. By Sunday afternoon that thing was either purring like a kitten or roaring like a lion depending on what the goal was.
Sometime the dead...they don't come back the same.
Pro-tip: 90% of the time your best solutions with an old clunker are 1. Replace HDD with SSD 2. Add more RAM (if possible) 3. Disable Secure Boot 4. Install lightweight Linux distro