Can an iPad 3 connect to a Windows 7 adhoc network with internet connection sharing enabled?
Yes this is definitely possible. I have created an ad hoc network on windows 7 and connected to it with my iPad 3.


Go to control panel > Network and Sharing Center
Click setup a new connection or network
Scroll down and choose Click setup a wireless ad hoc network
give a network name and choose WEP encryption from the dropdown list. The password should be 10 characters long and I used all numeric digits for this.
tick save this network. and click next at the bottom to create the network.
On your iPad or other device select your network which will be broadcast with the name you chose and connect to that network with the password yo uused in step 4.
If the device fails to connect, try repeating this process again. It took me a couple times but worked eventually.
After Connecting, you must also setup network sharing in order to connect to the internet. You must have an internet connection on either LAN or a different Wireless card or some other device. Go to the Network and Sharing Center again in COntrol Panel.
Choose on the left sidebar Change adapter settings to get to Network Connections
select the network connection that is connected to the internet (The LAN or alternate wireless / other device) and right click and choose properties.
Go to the Sharing tab and check Allow other network users to connect through this computer's internet connection.
Select the network connection that you were using to broadcast the ad hoc network for the associated network connection.
Click on the Settings button which will bring up a window with a list of services to allow or deny for users using this internet connection via the ad hoc ICS (internet connection sharing)
Check at least HTTP and probably HTTPS protocols, SMTP for email, POP3 for email as well if you need, etc... and Click Ok when you're done.
Click Ok again on the original window. In some cases you may need to restart the network connection connected to the internet for the changes to take effect.


I hope this helps!