Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Edit, courtesy of Google Translate:

I just installed Ubuntu 11.10 with my Windows 7 and when booting I get a black screen with a square moving across the screen that says "unsupported frequencies." After a minute I switch leads to Ubuntu users, but never gives me to choose Windows or anything. I wish I could fix it now that I have all my stuff in Windows and do not want to lose them.

Thanks in advance

Acabo de instalar Ubuntu 11.10 junto a mi Windows 7, y al arrancar el ordenador me sale una pantalla negra con un cuadrado moviéndose por toda la pantalla que dice "Frecuencias no soportadas". Al cabo de un minuto me lleva al selector de usuarios de Ubuntu, pero en ningún caso me da a elegir Windows ni nada. Me gustaría poder arreglarlo ya que tengo todas mis cosas en Windows y no quisiera perderlas.

Gracias de antemano

share|improve this question

Maybe your grub uses a resolution your Monitor does not support. I suggest to try the following:

  • boot ubuntu

  • edit the file /etc/default/grub as root and search the following line:


  • if applicable remove the leading '#'

  • set the setting to a value supported by your screen. You can as well set the color depth e.g.:


  • invoke the command update-grub as root:

    sudo update-grub

  • reboot

Be careful, mistakes in the grub configuration could lead to an unbootable system!

edit: also it might be necessary to increase the time you have for OS selection in grub2, if your monitor is too slow with adjusting grub could be gone before the monitor showed the bootloader menu use the setting:


also make sure that the following line is commented out with a leading '#':


dont forget to invoke update-grub after editing /etc/default/grub, else your changes wont become set.

share|improve this answer
If he can't boot Ubuntu, it might be rather hard to follow these instructions :) – tumbleweed Jan 6 '12 at 8:59
okay then i misunderstood you.i thought you could boot ubuntu but not windows because the bootmanager is not shown.Your system seems to be completely unbootable.maybe you can try to boot from the ubuntu live cd again and reinstall ubuntu.From the liveCD you should also be able to at least rescue your data from the windows partitions. – Michael K Jan 6 '12 at 10:26

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.