When USB flash drive should be unplugged?

Hello, I'm in a pretty hard situation with booting through USB and it's quite hard to explain but at the moment what I need to know for succeeding with the installation is, is it ok to unplug the USB flash drive after the first restart during the installation? My friend just told me that after it is done expanding the files and reaches 100% and does it's first restart, I can unplug the USB and it will continue it's job as all the files are saved on the HDD now.

Thought I'd ask here first before doing anything.

Installer may be needed after reboot, so I'd keep it plugged in unless it blocks restart.

With flash install I would set HD as first device to boot in BIOS setup, then trigger the stick to boot using only the one-time BIOS Boot Menu key given on first screen.

Asus - F8
HP/Compaq - Esc
Sony - F2
Acer - F12
Gateway - F10
eMachnes - F10
Toshiba - F12
Dell - F12
IBM/Lenovo - the blue Thinkvantage button

Well my BIOS is kind of weird.. The USB drive is not displayed in the Boot Sequence menu, but it appears in "Hard Disk Drives" menu. There I have 2 options
1st: SATA:4M-SAMSUNG HD
2nd: USB:ADATA USB Flash

So if I choose the first to be USB, then it gives me the option to choose USB as first boot device in the Boot Sequence menu, but then the SATA option disappears.

So my plan is this:
Set 1st hard drive to be USB flash, then select the USB flash to be first in Boot Sequence. Start the installer, let it expand files, do it's first restart, and then before the 2nd boot I go back to BIOS and set the USB back to 2nd hard drive, or just simply unplug it, but what if it won't be able to somehow read the USB flash drive, and what if it is needed for the complete installation? Then I'll be screwed.

That's why I'm afraid of doing anything.

EDIT: @ Brink - Thank you for the welcome, when I press F11 to pop up the Boot menu, it only shows CD/DVD and my HDD (Samsung SATA blablabla) no USB device, yet I have USB Legacy Support and options like that enabled.

So here is a video of my BIOS:


Any tips on how to get it to boot from USB? My CD/DVD doesn't work well, you put on the disk and the little lamp blinks and all that and that is all, so I thought I'd do it from a USB flash drive.

Incase the video doesn't play visit: http://www.youtube.com/watch?v=6d6MyC-QeJM

Your one-time BIOS Boot Menu may have a + next to HD's to expand and select the flash stick.

Be sure the stick is plugged in and reboot now into F11 menu to show us a video if it isnt' seen.

When you set stick to boot first in BIOS setup, does it block reboots or autostart on it's own?

Ok gregrocker I will try and see if I can use the + or something with the arrow keys, hope it gives more options.

@ karlsnooks - I guess I will risk and try doing it that way if gregrocker's method doesn't work.