3 Gb is slight larger than what a 32 bit Os can recognise,
So upgrading to more ram would be waste of money.
BDW why you need ram more than 3gb???????
Umm, No it's not, 32-bit OS can address 4GB of RAM however a chunk of memory is reserved for system use. (Kernel, etc) This is why when you have 4GB [of RAM] on a 32-bit OS you can end up with anywhere from about 3-3.5GB of RAM being actually usable. (Yes, you can end up with less but the amount is actually configurable!)
@OP: If you have 32-bit Vista (which you stated you do) then you should check if you can get the free upgrade to 64-bit Vista, as they have offered that, it is in that case that you would be able to upgrade to 64-bit Vista & then you can add more RAM & it'd be usable aswell.
yiuca, You took me wrong, I explained what a 32 bit system can use at maximum, I did not told about recognisation of RAM.
If you meant something completely different fair enough but on my side of things there is little room to misinterpret "3 Gb is slight larger than what a 32 bit Os can recognise" which to me looks like "a 32-bit OS can't recognize nor use more than a little less than 3GB" so I replied to it, but on the upside I would have posted what I did whether your reply were there or not. But let's not get caught up in some kind of argument or anything as at the end of the day we're both right to some extent, unless he went to 64-bit, buying more RAM would be a waste of money as you say, I were just adding on with the little details.