The logo is a little bit better, but think it can be better. The gradient doesn't look so smooth, the border of the characters neither. A higher resolution will solve this, I think. Now you can see the different pixels to good. Can you try your flame dea?
Also make a version of the "UBCD" picture for the forum:
Can you also make a ico file for the cd image, which gets displayed in explorer when you insert the disk? It look now like a CD drive with a CD (it is in the root of the cd.
For Mersenne Prime Test and Stresscpu2, no icon has to be made. I incorporated those programs in the cpustress image which has only a text interface (it boots faster). Sorry for that.
I like the idea of the antivirus icon (1e one). Maybe the red cross can be bigger or look like the red part of the following picture:
Maybe you can change the letter that the virus is eating to something different (more 'file' like, whatever that means