All started with this - my Windows 8.1 got very slow and shows 100% disk usage:

[![enter image description here](https://i.stack.imgur.com/akPYp.png)](https://i.stack.imgur.com/akPYp.png)

I started digging what's going on and found this - mongod.exe (which is running as a Windows service) utilizes the most I/O write bytes:

[![enter image description here](https://i.stack.imgur.com/rxtrD.png)](https://i.stack.imgur.com/rxtrD.png)

And it is just after Windows start. No any other programs are running. Only Windows Task Manager in order to look at I/O operations.

I don't know if it is the reason my system is slow, but want to know why mongod.exe does so and if it is indeed the reason how to solve it. And I want to continue using mongod as a windows service.