Ok I've been running my computer with 2.5 gigs in it and it has been running fine (my mother board is an asus dual channel memory. Right now I have 3 512mb in it and a 1 gig stick.. I went to go add another 1 gig stick to make it 3 gig, and all memory is corsair. Once I do this my computer restarts fine and one everything starts to load I get the blue screen of death... lol. Im not sure what to do. I did the chkdsk /f but nothing happened, any ideas?

Thank You.

This error message normally indicates a memory issue.Maybe be something as simple a mismatched speeds.
Try remoeing the newer stick of RAM and try it again.