Ok, i reseated all the ram, even swapped postioning of the sticks. No change.
Started it up today, it had enabled another 2gb so was reading 8gb, but after a shakey boot (restarted 2 or 3 times before getting to my windows log in screen) it finally made it to a desktop for about 10 seconds before BSOD'ing with an IRQL_NOT_LESS_OR_EQUAL error.
I'm baffled now, i'm gonna guess bad hardware but is it the RAM or Mobo?