Need to boot into linux ubuntu from iso on a usb thumb drive

I suggest u burn the iso fil into CD or DVD

Please make sure to burn it correctly  see this
https://help.ubuntu.com/community/BootFromCD

after this , please follow the instructions here
http://www.ubuntu.com/download/help/install-desktop-latest
please make sure you chose  install not try in the below screen

Hello, thank you.
I dont have a cd or dvd.
I have the usb drive and that is all

and the file is way too large for a cd.

ok , when u boot from the USB , did u see the above screenshot ?  if so did u choose  "Install Ubuntu" ?
From what you said before I think u chose "try Ubuntu"  which is not correct

when you say

I tried the -hdd and it just boots Ubuntu.

, what Ubuntu you mean here ?  the old bad one on the Hard disk or the on the usb drive ?

Use Unetbootin to write the ISO to a flash drive - simply copying the ISO file to the drive won't work.

ok I can try that thank you!  when I F12 to the boot menu, which do I choose:  usb-fdd, usb-zip, usb-cdrom, usb-hdd?

try to use usb-hdd  ( if no option to use flash drive )  
Also I want to make sure u did not just copy the iso file to the flash drive ( that's will not work )  , you will need to write the ISO file to the flash drive not to Copy the iso file to the flash  drive

What is the particular difference bwtn copying and "writing"?

imaging your flash has no files at all

if you copy then you will have only the ISO file in your flash drive ( Wrong )
If you write you will have so many files and folder in your flash drive ( you have actually extracted the iso file )  and that's correct

Tip
1- Better format your flash drive
2- Use a program like http://www.isotousb.com/   to write the iso to the flash drive

Ok thank you.  But is writing using Nero or do I do some other Windows function or software to write?

here is a nice article that will help you a lot

https://help.ubuntu.com/community/Installation/FromUSBStick



1- download to windows  http://www.linuxliveusb.com/en/download   ( Linux Live Usb Creator.  )


Once you have usb-creator.exe, run it and follow the same steps as described for Linux (point it at your .iso file or your Ubuntu CD-ROM, point it at your USB flash drive, make sure you have the right device selected, then "Make Startup Disk").

Notes

    Instead of usb-creator.exe you can use Unetbootin to create a bootable USB flash drive. http://unetbootin.sourceforge.net/
    You won't be able to select the USB flash drive if it wasn't formatted in a way that Windows can see it. You may have to format it using Windows Explorer in order for it to show up in a creator tool.

Ok thank you.  But is writing using Nero or do I do some other Windows function or software to write?

Please read above  , I'm not sure about NERO  ( if it can extract to flash drive then should be ok )  , but I think you better use  ( Linux Live Usb Creator.  )   http://www.linuxliveusb.com/en/download     , it is free

I created the cd and installed from that.  I will also try the usb drive I made.  Im getting i/o error/block on disk bad now, so I wonder if this hdd is bad.

Thank you, Mark88