can a 32bit Operating System use all 8 Gigs of ram with 64bit hardware

Weird question: In the office whe are discussing if whe have a machine that is 64bit infrastructure (hardware) with a 32bit OS (Server 2008 std) and 8 gigs of ram.

The OS detects the full 8 gigs of ram, BUT, being a 32 bit OS, will the OS use the full 8 gigs of ram?

How can we prove how much ram is really being used, or Windows Server is fooling everybody?

more: whe need some tests done, is there any benchmatking software out there for this purpose?

A 32-bit OS using PAE can access up to 64GB of physical memory, but a process running on it will still be restricted to 4GB unless it uses a hack such as AWE.

SQL Server definitely uses it with AWE enabled so there's your not-just-theoretical proof. Even without AWE, any one process could only access 2 GB but if you have multiple such processes you can use it all.