I removed the other downloads page when I found the cached/discontinued Toshiba Downloads page for your model here: Laptop Driver Downloads
The LAN driver
choices are on the second page. You'll need to rightclick>extract the zipped file, then rightclick the .exe to Run as Admin on the Toshiba.
If the driver for your model doesn't install then post back the information I requested for what is listed under Network Adapters in Device Manager. If there is not a model named, then trace the actual hardware device using this tool: Hardware Identification