Optical drives are nowadays less common on laptops which makes making bootable install medias a little easier. Yes, easier by requiring you to use USB thumb drives. There are different ways to achieve what you want and here is couple of examples how to transfer Linux install media to USB thumb drive on Windows and Mac OS X.
First you need to download the install media of your choice as ISO image which you want to transfer to your USB thumb drive. In theory you need a media which is meant for USB thumb drive or is a Hybrid ISO image but practically all modern distributions' media are Hybrid ISO images.
Plug in the USB thumb drive and format it with FAT32 file system
Download UNetbootin and transfer ISO content to USB thumb drive using UNetbootin.
- Select Diskimage and click the ". . ." button to find and open the ISO file. Make sure Type is USB drive and the Drive letter is what your Windows detect and click OK. Your ISO content will be copied to USB thumb drive.
- Next you also need to copy the ISO file that you used with UNetbootin to the root of the USB thumb drive, e.g. the ISO file should be F:\linuxmint-16-cinnamon-dvd-64bit.iso
Now you can proceed to boot up the machine that you want to install with e.g. Linux Mint 16.
Creating bootable USB thumb drive in Linux is much simpler. You just need install media which is meant for USB thumb drive or is a Hybrid ISO image. With hybrid images, you can simply write the content of the ISO and make a bootable USB stick which can install Linux by using the 'dd' command.
You just need to have the ISO image and one command:
$ sudo dd bs=4M if=linux-image.iso of=/dev/sdX oflag=direct
Where sdX is the device where your USB thumb drive is, e.g. sdb. If your system doesn't support 'oflag=direct', you can just leave it out as it is simply intended to speed up the process a bit. If you leave the bs-option off the default will be 512 bytes and takes forever.
Mac OS X
OS X's DiskUtil can't burn ISO images to USB and gives "Invalid argument" but fortunately just like with Linux also Mac OS X makes things easy for you. You just need the install media which is meant for USB thumb drive or is a Hybrid ISO image. With hybrid images, you can simply write the content of the ISO and make a bootable USB stick which can install Linux by using the 'dd' command.
$ dd if=linux-image.iso of=/dev/rdiskX bs=8192
Where rdiskX is the device where your USB thumb drive is, e.g. rdisk1. You can see the device (disk identifier) from DiskUtility.app by selecting your USB stick and checking the Device section.
It's useful to notice that on OS X you can use the '/dev/rdiskX' device which stands for raw disk and is much faster than the block level device '/dev/diskX' which is buffered and where data undergoes extra processing. For example rdiskX gives "823132160 bytes transferred in 625.470137 secs (1316022 bytes/sec)" and diskX gives "823132160 bytes transferred in 1296.675998 secs (634802 bytes/sec)".
If you get an error e.g. "dd: /dev/rdisk2: Resource busy" then you have to make sure the Mac OS X isn't using it and thus unmount it's partitions. Open the DiskUtility.app, and on your USB hard drive, unmount any of it's partitions. Do not eject the USB hard drive.