Help, 2 problems, with memory

[matejakezman]

1. i installed 2*256 DDR in my computer, i already had 512 MB.
when i started computer, i noticed ATI drivers were unistalled, so i let windows install them again.
it installed some wrong drivers.
after few minutes i got blue screen of dead that ati is caused some error.
after that computer restarted by itself.
i take out memory and install new drivers. and now computer works for more than hour.
ahy did i get blue screen?

2. windwos did not recognized 2*256 of RAM. Everest hoever displayed it, but it was still 512 MB of old memory, what is wrong?

My motherboard is
gigabyte 7vt600p
old memory is transcdent

new i kingston

 

[Gamingfreak]

your computer obviously doesnt like the new ram, its bad to mix brands of ram so i suggest u take it back and try to get the same brand u have now, if u cant do that then replace the old ram as well

 

[matejakezman]

no bios is not recognaising rams. only old one. old one is double sided.(rams on both sides)
i have 3 dimms slots on my motherbioard and everest shows them all.
memory is dual channel but im not sure if my mother board support it(it gigabyte 7vt600p).

what coud be wrong?

and how it is possibile that driveers of graphic card gone after inserting new RAM, and why have i got blue screen of dead when wrong drivers were installed