If you have a XP or Vista CD/ DVD try this:
sfc /scannow (note space)
If this fails (or you have no CD), open Control Panel,Add /Remove, Windows Components (left side bar) and uninstall Internet Explorer( or your internet program)
Restart Machine, This should reload your internet program
If you have independent software for your Motherboard, you may need to re-load this.
It could also be that your Firewall or Security settings are set too high.