One solution could be that you have 2 versions of python. So, go to the specific python's scripts directory and run: pip install numpy
If that too doesn't work, you can find the answers to this question on Why can't I import opencv3 even though the package is installed?, as stated by @Cut7er.
I have tried the solutions given to the above stated question myself also. But, they didn't work for me. So, another thing that you could try to use is this IDE called PyCharm. It ofcourse is much more beautiful that the IDLE, but it also has an inbuilt GUI controlled installation of binaries or packages. That would make things a lot easier. I have faced a lot of issues with packages for python and this IDE made things a lot easier. You can find it on https://www.jetbrains.com/pycharm/download/#section=windows.
You can also use anaconda. But, I found it a little difficult to use since, it has similar issues.
EDIT:
Seems like you are using PyCharm. But, you are installing libraries from your command prompt. So, see the answer to: ImportError: No module named 'bottle' - PyCharm. This answer guides you through how to install a certain library through your PyCharm window itself. So,
1) Go to Files>Settings
2) Search for "Interpreter" from the searching tab. Open the interpreter
3) You can now see a plus sign on the right. A click on it will open up a section on the left.
4) In the searching tab, search for numpy
or opencv
. Click on whichever module you want to install. And then click on the "install package" button on the bottom left. This will install the package for you.
5) Then click save. And run your file that says import cv/cv2
.
This should probably do the trick.
Hope it helps!