An ad hoc network connection is not automatically reconnected when you restart Windows Vista
You use a computer-to-computer (ad hoc) network connection in Windows Vista. When you restart Windows, the ad hoc network connection is not automatically reconnected.
Note: This issue may also occur when one of the following conditions is true:
- You forcibly close an ad hoc network connection by shutting down a wireless network.
- You disable and then enable the network adapters.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB957274.