The Toshiba Satellite laptops are pretty fussy when it comes to booting from a CD/DVD or USB Thumb drive. By default, the Toshiba only boots from UEFI devices - your thumb drive may be a different type. But you can change a setting in the Toshiba BIOS to boot from other types of drives.

Assuming your thumb drive is actually bootable ;)

If you are having troubles booting from a thumbdrive, try this...

• press F2 during a boot to get to BIOS.
  
  
• Select Advanced > System Configuration > Boot mode > CSM boot mode.
  
  
• Select Security > Secure Boot, and then Disabled
  
  
• Save and Exit BIOS