What I did to speed up my 2014 laptop, was to max out the ram storage, by adding the max to each slot. It has 2 slots. I was told that using all of the slots was better than using only 1 slot. For example, if the max RAM rated for a system is 8 GB, it's better to use 2 4GB sticks than to use one 8 GB sticks.
I had to remove the cover to the battery area, to expose the exact model number of the laptop. You want that to determine the exact stick to use.
Some devices, like some Chromebooks, do not have removeable RAM, so you're stuck with the RAM it comes with.
But many laptops do not come shipped with the maximum RAM loaded, that the device can handle.
There is a performance benefit to using dual-channel memory, but it's more for squeezing out extra performance in high-memory intensive apps like games, video encoding, etc.
With your computer, the larger benefit came from adding more memory I am sure. In a full windows system, I would not even consider running less than 8GB and if you run any process-intensive apps like games, video editing, photoshop, VM, etc., you should have at least 16GB.
Switching from mechanical (spinning) drives to solid state drives (SSD) will provide older computers with the biggest performance impact.
The reason for this is that even low memory systems can benefit from SSD due to paging. For those that don't know, when your system needs more memory than you have available, it creates a disk-based memory system (paging) which is why your computer can still function with low memory, though it will do so at a severe performance hit especially if you are using mechanical drives. Having the paging file stored on an SSD will provide a much faster memory alternative than if it were on a mechanical drive, but still not as fast as actual memory of course.
As I mentioned in my first post, the first thing anyone should do when their computer is running slow is to check the software/processes running in the task manager. If there is a problem there and you just throw more memory, faster drives, etc. at it, it won't necessarily fix or improve things. Software like Malware Bytes Free, SpyBot, etc. will help solve the malware issues and tweaking some Windows settings or updating Windows may help if windows itself is causing problems. For example, there is malware that does crypto-currency mining. It won't matter if you add a 4TB SSD drive and 32GB of memory to a system that's infected with that malware. It will simply increase its speed and absorb every new resource you added to the computer.
After eliminating or finding no software issues, the second thing you should do is replace the mechanical drives (or at least the boot drive) in your computer with an SSD. There is software to help make this process not overly complicated, but if you have very little tech skills, it may be better to pay a computer service or get someone who knows how to do it to handle the replacement.
Finally, the third thing you can do to improve performance is add memory, preferably dual-channel (more than one memory card).
Of course the easiest thing to do if you are not tech-savvy is to buy a new computer with current generation CPU, 8GB or more memory and an SSD, preferably "m.2" rather than "SATA".
