How to Access Boot Options 12.04 Live USB

EDIT: I've now gotten to the point where I can type in a boot line. I just need to know what to enter. Does anybody know what the default boot line for the Ubuntu Live CD is? After that I think I just need to add nomodeset and it should boot.

I'm attempting to install 12.04 on my computer but booting from my USB drive results in a blank screen. This has happened since 10.04 and has always been fixed by putting nomodeset in the boot command, but now I can't access the boot options with F6 for some reason. How can I access the boot options?

I booted into the live image on a different computer and it worked fine. I'm sure it's because of my Nvidia graphics.

When I boot into the live image it shows a small gray box in the lower left corner of the screen and that's it. I can't edit the boot options or do anything else.

Thanks in advance.

As soon as you start to boot from the USB, hit any key and the Ubuntu Menu will come up...

If you press F6 you will get the other boot options (in the gray box in the corner) selecting one or more will append it to the boot command automatically. If nomodeset doesn't work the next one to try would be apci=off. After selecting the extra boot commands select "Try Ubuntu" and see if it will boot.

You are likely right about the problem being your Nvidia card but solving that problem is beyond me. I think I was able to answer you initial question at least.