Installation Error

[isvan]

I am trying to install Ubunto on a external USB Hard drive. Every thing went fine till the last screen where you see the bar with the percentage of the installation process. In my case it stopped at 15% and it didn't go thru beyond this point. I waited 30 minutes and nothing, it stayed at 15%, any advice about this?

[Ub1476]

Have you checked the CD for errors? What process is it doing when it stopped (I think there's a detailed drop-down box)?

[isvan]

No error message, it stays in 15%, then after 30 minutes I close the window and the OS keeps working but When I hit Install again it doesn't work. After that I just click on shut down Ubuntu.