Should i upgrade my laptop?

I went from 2GB to 4GB and hardly noticed any difference. There is a lot of difference from 512MB to 2GB. But from 2 to 4, not very noticeable. After you have enough it just doesnt do much. Your 32-bit windows will only use 3.25 anyway. A 64bit os would make a lot of difference but costs more than 50 bucks.