The ASDFGH or QWERTY board is the standard key board from the days of typewriters to this day. You are supposed to type with both hands to type fast. However the DVORAK style keyboard can be used for typing with one hand, either left or right or both. It is supposed to be faster than the QWERTY.
This is one of the accessibility options in Windows XP which you can access from
Control Panel | Regional Languages (window) | Languages to open
Choose the style you prefer
You should be able to see this toolbar item added as shown
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