I recommend to accept, to leave everything as it is and not torturing the animal. Use it for what he lacks strength. Model You have not written, but chances are the memory is not expandable. Is that SSD a bit will improve the situation. The problem is not the OS, as in modern applications. If the browser eats memory gigabytes, then there is at least 7, at least XP, even Linux - one features.
The alive this EeePC. With 1 GB, and is soldered on the Board. But with passive cooling. Windows 7 Starter. Once stuck in a small ssd. So he now no mechanics and extra sounds. Sometimes lying on the sofa, I go with him to the Internet in the "easy" sites, forums. Took to the road in the car movies to watch. Take, when friends are asked to help the network to check the router to configure, etc., In total working slowly.