where do i get windows mobile 2003 and is it compatible with the x5 2003

I don't really know why you would want WM2003 if you already have WM2003 on the x5, but you can't buy them from dell.

You can check ebay, or the classified section here on aximsite. One thing to keep in mind though, most of the WM2003 OSs sold on ebay are illegal copies.

   

i am looking for a reason that my x5 won't connect to the internet.

Have you tried a hard reset and/or followed the wifi guide:

http://wifi.aximsite.com

A hard reset will put your X5 the way it was in its factory state so there's no need to buy WM2003.