Hi, and welcome to the forum
.
Since you have also posted a query, I have moved the thread to the proper forum, so that more people can post answers.
Regarding the RAM, how did you know it has a dimm RAM? It should be DDR most probably. You can confirm it, and also know more about the hardware, by using a system info tool like
SIW.
If the RAM is not sufficient, you can increase it, and that will speed up the system.
Other than that, you can defrag the system with softwares like Defraggler, MyDefrag, IObit Smart Defrag. That can have considerable effect, if the system has not been defragged from a long time.