Memtest86 bood disk problem

Hi

I have a sony vaio laptop with vista home edition.
yesterday I got a scary blue screen just before windows started..
the blue screen look like this :
ImageShack® - gk2k’s images

I think it’s a memory problem and I want to check my memory so I downloaded and created a boot cd
of memtest86.

I restart my laptop and boot the CD of memtest86, but it dosen’t starts the check, it just open a new DOS
look like this :
ImageShack - Hosting :: doswinpt6.jpg

does anyone has an idea what i’m doing wrong ?

thanks (: