Is windows7 (32bit) stopping me?

i have recently upgraded my pc, i bought an extra sata drive and some extra ram. the HDD works fine and im having trouble with the RAM i have purchased. i currently have 2x2GB sticks and since im about the to start using adobe products i bought another 2x2GB modules.

the problem i have is that the new memory modules work great but the pc doesnt want to work when i have all 4 modules in at once. when i have either of the pairs in alone the pc boots. but as soon as i try all 4 nothing happens. the fans work, green lights are going but just a black screen.

the mother board i have is a pegatron benecia 1.01 – which i seem to be struggling trying to find a website for.

thanks in advance for any help offered 🙂