I want to boot my computer from a memory stick but my bios onlny shows 2 possibilities:
1 The hard drive
2 The disc drive
You need to give more information. What is your computer make (HP Dell, etc?) and year it was manufactured? Do you know if it supports booting from a USB or Memory stick? A lot of computers did no until the last days of XP and the start of Vista? There are some that have work arounds, if you give some info.
Some BIOS have the possibility to display a boot menu to choose where to boot from, is there something like this displayed on your BIOS screen?
Is “Secure Boot” activated in BIOS and your using a USB-Stick for MBR (non-UEFI) as target system ? If yes the USB-Stick will not be shown in the Boot Menu. Try creating the bootable USB-Stick using UEFI as target system or deactivate “Secure Boot” (may not always be a good idea !) and use a bootable USB-Stick with MBR as target system.
This is my experience with 2 Acer notebooks (4 and 1 year(s) old).