How much data is used on the HDD?
Not knowing more, I would suggest a 240gb Samsung 850 EVO
https://www.newegg.com/Product/Product.aspx?Item=N82E16820147372
Samsung for several reasons.
Samsung is a bit faster than most and has a 5 year warranty.
Samsung offers a free ssd migration aid which will move your C drive to their ssd.
I suggest at least 240gb for windows C drive. Many things default to that so you do not want it getting full.
In the mean time, download the diagnostic program for your hard drive to see what might be going on.
WD and Seagate have them.
A reinitialization of the device might be enough to use it later for bulk storage.