I cleaned inside my old Dell computer. What upgrades do you suggest?

[RSV.]

Ok so I cleaned up my old grey Dell computer. I will clean it some more. So it was so nasty on the inside. Besides redoing the thermal paste what upgrades do you suggest? I want to upgrade it. Graphics card etc.. I still want to use it. I have not used it in a long time.

 

[Colif]

knowing its specs would aid in suggestions.

That looks like the dell keyboard my mum used to use until I gave get my old Corsair K70.
dell are still selling the same cases they had 20 years ago, just wrap them in plastic to make them look new.
You couldn't pay me enough to buy one.

 

[RSV.]

knowing its specs would aid in suggestions.

That looks like the dell keyboard my mum used to use until I gave get my old Corsair K70.
dell are still selling the same cases they had 20 years ago, just wrap them in plastic to make them look new.
You couldn't pay me enough to buy one.

Why may I ask?