Marcus thankyou.
Here are driver downloads:
Dell Dimension 8250
Now I see USB needs drivers.
I need you to download the chipset for me and run it.
Then in device manager I need you to right click on each USB device and choose update driver.Chipset includes drivers for your USB.
I asum under network that number 2 or number 12 are the driver you require.
Download them both and save do not rum.Then in device manager right click on the network adaptor and choose update and manulay locate the file.
You can download and run but you may find one works and one will not.