How old is the laptop?
If its new, check if its under warranty. Sometimes something on your motherboard goes bad, and you gotta either get the board replaced, or get a new machine. Its not unique to Toshiba, as I've seen plenty of Sony, HP, Compaq, etc.

I'd highly recommend you take it to a local technician to see if they can get something more out of it if the computer is not under warranty and is not over a year old.

If its a really old laptop, I'd say get another one, cause if the motherboard is bad, then you're pretty much going to pay more in parts and labor than its worth.

download Hiren's BootCD, it have a lot of stuff (diagnostics,partitioning,recovering etc.) burn it on an CD and boot it...before you boot it read what it contains and see which tool is best for your problem or you can print that...it helps me in a lot of situations...