can't bake

hi everyone
i watched a video about createing a dragon on blender cookie by a man named david ward. when he textureized the dragon he duplicated it then turned up the rezolution on the duplicate and sculpted the scales. then he used that to turn it into a normal map by bakeing it. (dose that make sense?) anyway when i tried it, my computer crashed when i pressed bake. i spent ages trying to get the texture right and i don’t whant it to go to waste. can anyone help?

If it’s a real large texture then it may be a RAM issue, do you get the same crash when you try smaller texture sizes?

no. it probably is. is there any way around it? i tried to upload the file but it was too large. i just got a new PC so i’ll give it another go.