Look for clues what works and what doesn't.
- Try disabling security software for the time being
- Sometimes certain hardware won't get a correct IP
- Try getting a new IP address (ipconfig /release and then ipconfig /renew on Windows) or set a static one
- Can you connect to the router and not the Internet?
- Do a ping test of your router, your modem and a site
- When connecting via Ethernet, disable Wireless
- Test whether the issue is only related to this computer
- Test whether the router 'sees' you
- Test whether other hardware (a different modem/router) fixes the problem
- Have you installed any strange/new software recently?
- On Linux the drivers might be the problem, try proprietary drivers for example
- Reset everything (including any routers/modems you use/connect to) to the defaults (including reinstalling Windows that came with the laptop) and use that
- Sometimes the defaults of a router don't work for certain hardware, so disable all 'exotic' features of the router/modem
After going through all that and still not have a working connection to either the network or the Internet, my guess would be broken hardware. With a) default working settings on the modem/router b) OEM software supplied by Toshiba c) defaults for those software (including BIOS) by reinstall and lastly d) both ethernet and wireless connections not working, I don't think there is anything we can do.
Free your mind / Think clearly