I purchased a PS3 from a Pound Shop that had the previous user's data on it. After deleting all the previous user's data from the system, I was able to download a game and play it. My son has another game that he would like to play; however, when I try to install it, it says the system does not have enough free space. I tried resetting the system multiple times, but to no avail. Do I have to uninstall a game every time I want to install a new one? There's another PS3 that is the same model as the one I own, and that one can hold five games without any issues. What do I need to do in order to install multiple games on my PS3?
The PS3 can come with an extremely small HDD. You can buy a bigger hard drive, however you'll need to know how to replace it. You can find a lot of videos on how to do this online.
Here's a PS3 HDD that I found just by doing a quick search on Amazon: http://www.amazon.co.uk/gp/product/B00SWXYDBY and this tutorial should help: