how can i fix toshiba satelite l30?

It is most likeley a hard ware problem.
You dont say at which part it freezes. EG does it freeze in windows, if it does then it may be a windows application or driver, even a virus, or a faulty peice of hardware.
Boot it up and enter the LAptops Bios and check to see if there is any problems. if if locks up in the bios then it will be a hardware fault. at this point seek advice from the manufacturer. If its under warranty still then i would advise to speak to the manufacturer before implementing any fix.

Oracle9I
October 2008