Where can i download a config utility for my D-LINK AIRPLUS DWL-G510 ADAPTER

Here is the site for the driver.
http://www.dlink.com/products/?tab=3&pid=DWL-G510&rev=DWL-G510

Dlink does not have a configuration utility for this device, so it may be that there was not one offered. Instead you can use the zero configuration utility with Windows XP.

It also states that this device has been discontinued; the driver is the 1st release driver and has not been updated.

select the DWL-G510 driver to download it, or if you have the h/w rev.2 click the FAQ and select the option for a missing "wlanapi.dll" file. There is an updated driver for this revision on the link to that FAQ resolution. For ease of use it is here:
http://www.dlink.com/products/?tab=3&pid=DWL-G510&rev=DWL-G510_revB

Good luck and I hope this helps.