Operating System: Microsoft Windows XP Professional 5.1 Build 2600
System Manufacture: Dell.inc
System Model: DV051
BIOS: Pheonix Rom BIOS Plus Version 1.10 A04
Processer: Intel (R) Pentium (R) 4 CPU 2.80 GHz
Direct X Version: 9.0c (4.09.0000.0904)
Even if your Motherboard would support it, your CPU is too slow.
If you want to upgrade your Computer, you would be better off building yourself a new PC. Something like a i3 2120 with a 6850 would easilly run Diablo 3 Maxed out.