Hi I have just installed 2 GB of memory into the 2 vacant memory slots of my motherboard I already had 1 GB of memory but these are the reading I get from my computer - XP pro 
from Belarc Advisor
Board: Gigabyte Technology Co., Ltd. 8S648FXP-RZ
Bus Clock: 200 megahertz
BIOS: Award Software International, Inc. F2 11/02/2004
1024 Megabytes Installed Memory
Slot 'A0' has 1024 MB
Slot 'A1' is Empty
Slot '' is Empty
From System Information
Total Physical Memory 1,024.00 MB
Available Physical Memory 619.36 MB
Total Virtual Memory 2.00 GB
Available Virtual Memory 1.96 MB
Any help appreciated
from Belarc Advisor
Board: Gigabyte Technology Co., Ltd. 8S648FXP-RZ
Bus Clock: 200 megahertz
BIOS: Award Software International, Inc. F2 11/02/2004
1024 Megabytes Installed Memory
Slot 'A0' has 1024 MB
Slot 'A1' is Empty
Slot '' is Empty
From System Information
Total Physical Memory 1,024.00 MB
Available Physical Memory 619.36 MB
Total Virtual Memory 2.00 GB
Available Virtual Memory 1.96 MB
Any help appreciated