Not enough RAM memory [Duplicate discussion. Locked.]

So I posted earlier:  (I'm about as computer illiterate as can be. It's a new laptop that has 4GB DDR4 system memory and 1TB hard drive storage, whatever all that implies. There's barely anything on it. I'm learning PSE and was able to save a project with no problem. When I went to save another project 3 minutes later, I was not able to. I kept getting the "not enough RAM memory" pop up. I've read through some of the solutions, but they all appear very intimidating and beyond my know how.).            

Now I'm being told by Adobe that Windows 10 is not compatible with PSE 18 and that I need to pay $99.00 to upgrade to PSE 20. I think this is rather unfair. Does anybody have a different solution?