IE Connection Dropping

[Nismo]

There is a PC with IE connectivity issues. If they go away for a few hours or log on in teh morning, IE has no connection. They have to restart the machine for a fix. Everything else on teh network works fine when thsi problem occurs. I can ping and check mail.

I turnned off all the power option in control panel. I also unchecked the NIC hardware properties to save power on sleep mode.

Still not fixed.

 

[Nismo]

more info:
No Windows NT or Windows 2000 Domain Controller is available for domain USERSAPPLGE. The following error occurred:
The RPC server is unavailable. event id:5719

This event happens every time the problem comes up when away from desk.