Several of our clients face this issue with their PC recently.
So I thought I can share a tip with you, as you may possibly face this similar problem.
Well, the problem is: S.L.O.W.N.E.S.S
Whether you like it or not, Microsoft pushes out many updates especially for Windows 10.
I have 1 actionable tip for you, and I suggest you do this just before you go for your lunch breaks. The whole process may take up to an hour depending on your hard disk size.
It works even if you are using another version of Windows like Windows 7...
Tip # 1: Defrag (Time require: 2 min)