Good board with Startproblemem

I've got this board as the successor for my D2700 Atom PC.
Win7 HP 32bit could be installed very quickly and ran stably.
After the initial setup struck me were just 1,83GB available from 4GB Ram -> about 2,2GB "hardware reserved memory."
Google could not help me legally.
Eventually, I came across the ASRock A-Tuning -> Lets you attach a virtual HD set (RAM disk), on which the swap file and temp data come.
So set up and noticed no difference from before.

So once brought to 4GB -> ramdisk went by itself up to more than 6GB, accessible memory stayed with 1,83GB
ASRock written -> that would be in 32-bit operating systems normal -> BIOS update, then you come to 2,7GB memory.
No sooner said than done -> directly regret: alone while browsing with Chrome every few minutes the message, that is not enough main memory.

From the network ne 64bit version of Windows (32-bit key remains valid) pulled installed -> 7,7GB memory available.
Installing Win7, Office 2010 and all other MEMBERS PROGRAMS no 3 hours. 50GB installations for backup (SATA6-> SATA3) in about 8min.

With the 64-bit version, the computer is running very well.
The only thing that does not work anyway, is the fan control, the are always full throttle.
Since the board is designed for passive cooling, the fan remains disconnected.