Screen artifacts

I took the oppurtunity buying MV during the summer sale and there seems to be a technical issue on my end. Whenever I open and close the menu a few times after each other green and purple block artifacts spawn all over. They dissapear once the menu is cancelled out of but reappear in text boxes.

I have updated my graphics card driver (NVidia GForce, has OpenGL), my DirectX and installed Java. I have over four gigs of memory and my processor has four cores. Available storage is about 700 gb. I have also tested restarting the graphics card and running MV without Opera running in the background. I own the non-Steam version.

This use to happen when I work in Photoshop and have too many things running at once and get better when I change working disks. But I can't understand why MV is having issues. Do I need to downgrade my graphics card drivers or deep clean all the fans or something?

1) java and directX have absolutely nothing to do with MV.
MV uses javascript, and as the saying goes - java is to javascript as ham is to hamster, they have absolutely nothing to do with each other.
And MV doesn't use DirectX (which exists only for windows anyway) but OpenGL (which is supported on multiple systems including MacOS and Linux, that's why you can run RMMV on those OS.

2) Can you give a screenshot of those fragments?
We need a better description to even guess what this might be.