Hardware reserved memory issue

The hardware reserved memory has nothing to do with Windows 7/Server 2008 R2, it's just that earlier versions of Window's didn't point it out to you this clearly. On my work laptop Windows 7 shows 31 MB of system reserved and when I was running Windows XP, (looking closely I can't remember where), it showed that I had 4064 MB available (when I had 4096 MB installed).

You will have to examine your hardware to determine the cause of the reserved memory, but I doubt there is anything that you can do.

Edit based on hardware description:

According to HP your laptop has an Intel 945 chipset. That chipset only does 32bit addressing so you won't be able to use all 4GB of your RAM, since some of that address space is reserved for hardware IO. Even running 64 bit Windows, you're stuck with 32 bits of hardware address space because of the chipset