Sorry, I don't how to use my iPad as a second monitor, but I know how to use my iPod as a disk mode, here is article about how to set iPod in disk mode. maybe it can help you.
This works only with Windows 7 !
Step 1: Download the App Display Link
Step 2: Download This Software (Restart Required)
Step 3: Enter A Password
Step 4: Make sure iPad and Computer are connected to the same WiFi
Step 5: Start the App
Step 6: Click your PC and enter the password you set during Step 3
Your iPad will now appear as an extended display and if you wish you can change it to mirror the desktop through windows.
Sorry, I don't how to use my iPad as a second monitor, but I know how to use my iPod as a disk mode, here is article about how to set iPod in disk mode. maybe it can help you.
Leeched /msg2short
Please press Thanks/Rep+ me if I helped you in anyway
"Gangsters used to move ounces and reach for burners.
Now gangsters only move mouses and reach for cursors."
-Token