One question that I get asked alot is how to create a bootable USB disk especially for installation for ESX and Linux distros. There are probably multiple ways to do this but I effectly use a free tool call UNetbootin, this utility has binaries for Windows, Linux and Mac so works great whatever your desktop of choice, now burning CDs becomes a thing of the past.
2. Download the VMware vSphere 5 ISO file -> VMware Download Center.
3. Start the UNetbootin application and choose Diskimage (ISO) and browse to the downloaded ISO file.
4. Choose Type: USB Drive and choose the correct USB drive letter that you want the bootable installer to be installed to( make sure your USB drive is formatted as FAT32 and not NTFS)
5. You are now done! Just make sure you select the correct boot sequence in your BIOS so that the USB drive boots first.