What is maximum memory Windows 32bit can utilise?

Q. What is maximum memory Windows 32bit can utilise?
A. The maximum amount of memory that your system can use is actually limited in two ways — not only is there a maximum amount of memory that your computer motherboard can accept, there is also a maximum amount of memory that your operating system (OS) can accept.
For instance, when you install 4GB of memory in a 32-bit Windows system (the most common version; 64-bit systems are typically used only by high-end users), your system will see (and utilize) only 3GB or 3.5GB.
Is the problem bad memory?
Relax, there isn’t a problem with the memory. Windows allows for 4GB of memory to be addressed, but this isn’t 100 % the same as having 4GB of physical memory.
What happens is that some of the addressable memory (regardless of how much you have physically installed) is reserved for use by page files or by some of the devices that you are using, such as a graphics card, PCI card, integrated network connections, etc., so it’s unavailable for use as normal main memory.
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