You may have a bad installation. Linux should not freeze. Always check the checksum of your download before puting it on the disk or usb stick; always burn the disk at minimum speed; if the distro offers to check the installation disk (and Ubuntu does), do it.

I can't speak for Ubuntu, as it won't run on this computer, but I find PCLinuxOS, AntiX MX, Salix, and Point are generally good.

PS I've just noticed you're from Brasil. The Portuguese government produce a great distro, Caixa Mágica:
http://www.linuxquestions.org/review...page/15/sort/7

Is there any info on what hardware is being used?

I agree MS Office and LibreOffice/OpenOffice are not quite compatible yet. It is frustrating when uni supplies templates we must use for assignments and they look screwy in LibreOffice. That is not an Ubuntu problem though.

What kind of teacher? Not in a real school I hope. I would be worried if a professional teacher teaching others how to use Linux was using Ubuntu or Mint him or herself. Although it would partially explain the screwed-up nature of Linux's current user base.

As for your question about what to do. Easy answer. Use a different distribution. There are many distros, with some being good and others not. ;)

Thank you for reply!
 

Dear friend. Thank you for the hint. I will make another installation disk carefuly to chek if that improves. I also will look for Caixa Magica!. Huggies.

http://linux.caixamagica.pt/pag/a_index.php