Well, I don't know your system, so if could give some more information, in might be helpful.
I have had this problem before when I had a 3-Com network card (3C-905B or 3C-905C to be specific), when it was not connected to a network. The system hangs for quite a while trying to initialize the network.
If you have a NIC in your system and are NOT connected to a network at this time, go into your device manager and disable the network card.
For a step by step:
Go into control panel and go to system
Choose the Device Manager tab.
Under Network adaptors, double click you network adaptor (not Dial-Up adaptor or AOL adaptor)
Check "Disable in all profiles" ( wording may vary depending on version).
Click Ok
If this is not your case, let me know what is in your system, and I might be able to provide more help.
Jeremy Hannon
Brainbench "Most Valuable Professional" for Computer Technicians