1)First of all make sure no drivers are installed for your wifi usb so windows recognizes new device.
2) Download this latest Vista Driver, I uploaded to megaupload:
http://www.megaupload.com/?d=D06GSMK3 .Download it and install it.
3) After installing it, go to My Computer> Local Disk (C.)> Program Files> ZyDAS Technology Corporation>ZyDAS_802.11g_Utility>
You will something called ZDWlan.exe , Right-click on it and press properties. Go to Compatibility Tab and tick Run this program as Administrator and tick Run this program in compatibility for: Choose Windows 2000. Press Apply and Ok.
4) Now plug in your Wifi USB and just allow Windows to automatically install the drivers which is going to be wrong but just allow it and we will change the drivers to the location to the one you previously installed. (Make sure you have Internet on your PC right now so it can search for drivers)
5)Once the wrong Windows Drivers successfully install. Right-Click on My Computer and on the left press Device Manager (Make Sure Wi-Fi USB is still plugged in). Once the window of Device Manager comes up look for Network Adapters and press the the Plus to show the adapters, you should see your Internet Network Card and the wrong adapter for your Wi-Fi USB which should be called Atheros something by default in Vista.
6) If you do see Atheros Adapter or something else then Double-Click it and go to Driver Tab and press the Update Driver button. Press then Browse My Computer for driver software> In the location you should put C:\Program Files\ZyDAS Technology Corporation\ZyDAS_802.11g_Utility\InsDrv... and make sure include subfolders is ticked. then press next and it will install the correct and latest drivers for you Wi-Fi USB. After it is installed, it's better to restart the computer.
7) After it is restarted, Plug in your Wi-Fi USB and open that ZDWlan.exe program you installed, make a shortcut to your desktop to make it easier to use later. The program should load up and you can use the USB from there to search for Wireless Networks or create your own Wireless Access Point.
Took me a while to figure all that out and write it myself. Hope that helps. If you have any questions than just ask and I will gladly help cause I have a EDUP Wi-Fi USB and have Vista which had trouble when I bought it at the start but after using this method it works perfectly with my PSP and other devices to connect to.
