Windows 10: Why is my laptop slow and how to solve it?

I have an ASUS TUF F15 that has a 512GB SSD. Sometimes it starts lagging and if I open the task manager, the disk is almost 100% used but the read/write rate is extremely slow like 10KB-5MB per seconds. I was thinking if it is a problem with my disk but if I restart my laptop, this problem usually goes away. What can be the problem? And what is the solution? Here's a screenshot of my task manager when such problem occurs:

:)

 

HELP! My Laptop has gone into SLOW MOTION!

Should be able to get a "step-by-step here;

http://support.dell.com/?~ck=mn

 

Best laptop under $800??

Well the last one I suggested seems to be the best for 650$

EDIT: to facilitate your search...

Laptop GFX benchmark list

Laptop CPU Benchmark list

 

Solved

Solved! or fixed! or whatever! I was able to absorb the extra space in a 3-step process:

1. resize the System Reserved partition to use the space after it
2. reboot
3. stretch the M: data partition to absorb the space after it using the EXTEND -- not RESIZE -- command

System rebooted and working normally. THX all.