My favorite trick to reviving old computers is trying to find ways to get them to run off of solid state storage. It really makes a huge difference. You will be surprised by how much more tolerable classic computers are when you no longer have to deal with slow storage mediums.

Mind you this doesn’t make them modern levels of fast and you no longer get the satisfaction of hearing the hard drive grinding away when you open a window but thems the tradeoffs…sigh…