I have 4GB of RAM in my laptop with vista 32-bit, in some places it ses i got 4gb(inc bios) is all being used?

32 bit OS only has a maximum of 4GB to be detected. then some are to be reserved for your video cards memory. the bigger the video card memory, the bigger you think you're not using in your 4GB total of memory. usually, 32-bit os can read and utilize around 3.2GB-3.5GB of ram. you still have that 4GB total of memory, you are using it but the 32bit OS cannot utilize all of it.