Hard to say in most cases it's a simple driver issue, however that does not rule out the possibility of a hardware issue as in Network card.
How to replace a wifi card see video, just for information. I don't recommend you taking the Laptop apart unless you have some experience.
How to replace wificard
That would be the way to do it, that's just like reformatting and reinstalling so you need to save any files you want.
I think that there is a Toshiba suite pre-loaded that will do factory settings for me
These are some of the instructions I have found on how to proceed:
1. Restart the laptop.
2. Repeatedly tap the F8 key until you see the Advanced Boot Options screen.
3. Select Repair Your Computer[/b[ and press Enter.
4. Select your country and click Next.
5. Logon as a local user.
6. On the [b]System Recovery Options screen select TOSHIBA HDD Recovery.
7. Follow the on-screen instructions from here on.