Do old computers have any resale value?

I finally upgraded my 13 year old computer. There is nothing wrong with it, it is just old and only runs XP. I would keep it if windows 8 would fit on it. Anyway, does it have any resale value, or should I just junk it?

Very little. Computers don't wear out, they go obsolete. People want to upgrade every few years so 4 and 5 year old computers are 'a drug on the market'.

Go on your local Craigslist and look at computers, and set the price filter for $100, or even $50, and see how many perfectly good, nearly new computers you see that are just a little older and slower than a new computer. If you know someone who's upgrading, you might get their old computer for nothing!