My toshiba L300 keeps goin to a blue screen during

For that you need recovery disk.
Put that disk in cd/dvd rom.
Then when you power up the computer press F1 or F2 or "del" key to enter in bios.
Then go to boot option then set first boot device as your cd/dvd rom then save settings and exit.
Then it boot with that recovery disk then follow the procedure and choose "R" for recovery console then type in prompt "chkdsk /r"
then press "y
then it fix error on harddisk.
Then check if still same blue screen then you have to repair your windows.For again boot with disk then repair your old windows.
Let me know if you need more assistance.
Thanks.