? What black window ?
I just use Prime95 x64.
The only thing i change is doing a "custom" blend test by increasing the memory to all my free available memory on my system which is usually 6.7gb for 8gb. Otherwise prime95 will default to testing only 1.6gb.
linX can tell you your free available memory by clicking on the "all" button next to memory after linX loads up.
You can also change the min/max FFT's to 720k size for Prime95 custom blend if you want but that will just mostly test memory and not the whole system overclock stability.
i7-3770k 4.8ghz 1.21-1.24v Delidded 3231B415
i7-2600k 4.8ghz L041C108 1.32v PLL off Venomous-X Push/Pull
Asus P8P67 Vanilla
Samsung 30nm MV-3V4G3D/US 2x4GB @ 9-10-10-28 1T DDR3 2133 1.6v
Diamond HD 7970
CM 690 II Advanced