My computer boots, but won't boot from USB

[aka_biscuits]

Alright, so I downloaded Ubuntu from a computer running OSX and my computer won't boot from the usb drive. How do I go about fixing this? I opened the file using "The unarchiver" but it still wont boot. How do I go about fixing this?

 

[USAFRet]

Alright, so I downloaded Ubuntu from a computer running OSX and my computer won't boot from the usb drive. How do I go about fixing this? I opened the file using "The unarchiver" but it still wont boot. How do I go about fixing this?

You need to create a bootable USB. Simply 'unarchiving' does not do it.
See PendriveLinux

 

[skittle]

Use unetbootin. Should work just fine on Mac.
http://unetbootin.sourceforge.net