Windows 7 Windows 7: Addressing 3GB Memory Limitation and Low Memory Warnings

I am using Win 7 home edition 32 bits. I have 4 GB of memory.
Two questions:
1) For some reason Windows only acknowledges 3 GB. I know it's there because when I boot to Linux it reports 4 GB
2) I keep on getting low memory warnings when I don't have that much stuff running. When i look at te system manager, I am not using any where near 3 GB.

This has become so frustratin taht I have ginin up using Windows and just run linux

Any thoughts would be appreciated

tnx
marty