Looks like its SATA compatible so it can be done, however if space and money are an issue then getting a faster speed HDD would not be a bad idea, 1 TB hard drives are dirt cheap compared to the inflated prices of SSD's right now, its a sacrifice in speed for space but a 7200 RPM hard drive is still very fast.
Now there is one other thing to consider for this, once you give it more RAM and another hard disk you may want to convert this into a linux machine.
Windows 10 is on the heavy side, windows XP is out of date as is vista.
Linux may actually save this old timer, if you never heard of it well dont worry as you are probably already using it if you use an android as android is based on linux.
As as are chromebooks too.
If you have another machine to play around with I can give suggestions on Linux versions to try.
If your father is new to computers all the better, as it makes them more open to linux as linux is actually easier than windows in a lot of areas.
Its more teaching yourself linux is where this may start to be odd but its a nice suggestion as windows may drag on that hardware.
And linux can do most of one can want on a computer like go on social media, youtube, netflix, play web based games and might actually be better for someone who is afraid of catching a computer virus.
Sure its not bulletproof but fear is one thing holding some people back from computers.
As for your own computing issues, did you clean your machine out?
Did you make sure its free of dust and particles?
Edited by MadmanRB, 13 November 2017 - 10:37 AM.