Laptop getting freeze and delayed response - Dell Inspiron 3567

Jan 30, 2019
I have Dell Inspiron 3567 laptop. From the first day it's lagging problem is there it's getting freeze sometime and while working on chrome that time it's memory usage is getting very high!! don't know why so I'm using firefox and opera currently and also while opening any file or any type of content it will take few seconds to respond!

Is it a RAM issue or anything else ?

specs are:
Dell Inspiron 15 3567
Processor - intel core i3 7020U CPU @ 2.
RAM - 4 GB
Windows 10
64 Bit OS