Can 32 bit vista handle 4GB RAM?

[winstonli]

I had 4GB RAM installed in my T500 with Vista 32 bit and I can only see 2519 MB total physical memory in Task Manager. I googled the problem and found out 32 bit can not use full 4GB RAM. Strangely, if the max of 32 bit operating system is 4GB RAM, why can't it use them all? I have no intention of using more than 4GB RAM, so should I install 64 bit Vista? If I stay with 32 bit, is there a solution to have all the 4GB?

Thanks!

[tinue]

The adressable 4GB includes everything that needs to be mapped to a memory address: ROM, Video RAM etc. That's why there is anything between 2.5 and (at the very most) 3.5 GB of RAM that can be used in Vista 32. How much is usable depends entirely on the system, and can't be tweaked by the user.
To use all of the 4GB, you have to install Vista 64.

Regards, Martin