Ok, I'll try:

First I make a Plygon cube and I scale it abit.
Then I go to Hypershade, and choose the Blinn.
I double click the blinn, so I can get the settings for the blinn.
Then I go into Specular Shading and set the Reflectivity to 1.000.
And I also chance the Specular color to Black.
After that, I take my blinn and assign it to the Polygon cube.

Then I make a Polygon Sphere, scale it abit and place it just beside my Polygon cube.
After that, I go to my "Display Render Settings Window" (That's the global render, Right?) which are at my status bar.
Then I go to Raytracin Quality and enable the Raytracing, and I close the window. At the end I go to "Render the current frame" Which also is in my status bar.

When I've done that there is no reflection in the cube.

Hope you can help me.