Go to network connections. Right clic - properties on wireless network connection --> ip4 properties and then:
ip adress: 192.168.0.1
subnet mask: 255.255.255.0
leave the others in blank.
then right clic - propertiers on local area connection. sharing tab and allow the two options.
Now you should have internet on your cell. But anytime you turn on the pc must clic on the net icon in the taskbar, clic on you ad hoc, and clic connect.
But if you make a bat with the code above and put it in the startup now you shouldn't have problem...