my motherboard is crap

hi,
why my asus motherboard p5b-vm don´t find the 4gb ram, only foun 2,75gb on 32 and 64 bit windows 7?

-Did you try updating the BIOS?
-Did you try different RAM?
-Are you CERTAIN you had the same EXACT results on 64-bit?
-Try enabling MEMORY MAPPING in your BIOS (could be called the "MMIO" setting). I had users complaining about only 2GB showing up in XP 32-bit even though 4GB was installed. I went into the BIOS and found this memory mapping IO setting and enabled it and it bumped them to 3GB
-Lastly, check to see if your video card has an option to use system memory

LOL Boss man we need alot more info that just that..
full spec or just post up in signature

+1. Not hte motherboard, there is a setting in the bios or windows you are missing.

Sometimes you get that effect with crappy high density ram like the OEM builders use or that you see sold on ebay.