I just built my computer. Brand new everything. I tried to install ubuntu. I filled out the screen that asks you to assign a name to the computer, create a password, etc. When tried to continue, the screen said that I had an "unofficial copy" of ubuntu. What did I do wrong.
Now when I put a usb in the screen is black and says GNR GRUB version 2.02 at the top. What do I do from here? I've been Googling all day and have gotten nowhere. I tried boot-repair-disc and nothing happened.
I'd try to repeat from the beginning. Try the first answer in here: How do I install Ubuntu?
Especially the first 7 steps or so may solve your problem. If you think you did everything there right and used the official download source and the downloaded iso was not damaged, maybe an other answer here can help you.
Note that you eventually have to call the boot manager with pressing F11 or DEL while booting to select your usb boot device and start installation, instead of booting into your broken installation. (Note: This is what helped the questioner. See comments.)
To assure a correct download, you can use a bittorrent downloader application to download the iso. This is especially useful if you have a slow or unreliable internet connection. You can find the .torrent files for ubuntu here: http://www.ubuntu.com/download/alternative-downloads
