When I place my Windows XP Professional computer into hibernation and then switch on again, I am unable to gain access to the internet or Outlook Express. Sometimes there is an error message. The only guaranteed way to access the internet is to restart the computer.
John Zeal

You don’t say how you connect to the internet but the most likely cause of the problem is that the computer connects to the internet with a modem, either dial-up or broadband. The solution is to disconnect from the internet before putting the computer in hibernation or sleep mode. The computer expects to find everything in the same state on starting as it was when it shut down.

If the computer is connected with a modem, the connection is broken when the computer hibernates but the PC doesn’t know this. The computer can be disconnected from the internet by left-clicking on the icon in the Notification Area with two small computers connected with a wire. Select disconnect and you can hibernate the computer safely.