Cannot find and import heightmaps

ive been trying for a long time trying to import this height map called terrain.raw and i can see it in windows explorer but when i try to import it, it only shows files and folders instead of raw heightmaps. ive even tried switching between raw files and all files but no success. I run on windows 10 home edition on a lenovo yoga 300. Plz help, im raging.

Ok, so i found the solution. If anyone else is having the trouble, my file was in a zipped folder so all i did was take the raw file out into the desktop and I could finally view and import it. But the problem is that the heightmap doesnt really work and all I could see is a bunch of sharp lines plz help fast!