I just installed a new hard drive and for the life of me, I cannot get the .iso file on my USB stick or burned CD to begin the installation process.
I keep getting a picture of a folder with a question mark on it....
Assuming you're burning/writing it correctly according to these instructions...
...the problem might be that you're using the wrong ISO image.
So, if you're trying to install the 64-bit version of Ubuntu on a Mac, you should use the special ISO image for that purpose. It is called the 64-bit Mac (AMD64) desktop CD.
Just copying the ISO file to the USB, or burning the file to the CD will not work.
Please insert a blank CD and open Disk Utility to burn the ISO (the ISO will refuse to mount if you just double-click it)
Make sure you have the entire ISO file downloaded. It should be 981MB. Twice I downloaded the iso from the site, but it wasn't the full file although there were no errors with the D/L or indications that it didn't complete.