Seems normal. Windows XP is a 32-bit OS, so it's limited to 4GB of RAM. You'll need to move to Vista or Windows 7 x64 in order to make use of that extra 4GB of RAM.
As for the second problem, if the driver isn't on the Dell driver CD, that means that it is something you added, so that should help narrow down the possibilities. Of course make sure you aren't just having Windows scan the Dell driver CD, because the drivers are stored in a self-extracting archive, which you have to run before the driver files are extracted and able to be used.
I had to reinstall my Windows XO Pro to my Dell XPS 5 desktop. Everything s working at this point but I see 2 probleims:
8GB Memmory instaled in my desktop but MyComputer/Property shows only 3.25 GB. Bios showes 8GB (4GB was previously upgraded and worked fine before the Windows reinstall)
Devise Manager shows a yellow question mark at Other Devise/SM Bus Controller
When I go to properties here I see location: PCI bus 0, device 31, function 3
Status: The drivers for this devise are not installed (code 2
Device ID: PCI\VEN_8086&DEV_27DA&SUBSYS_01A01028&REV_01\3&172E68DD&0&FB
If I delete this device the Wizard finds it and looks for the driver but the driver is not found on the original Dell Driver CD.
What is this hardware? Where is it?