problem with grub

[forsubhi]

I installed ubuntu 10.04 on virtualbox and
sudo apt-get install linux-image-rt linux-headers-rt
on it to enable realtime , but when I power on the machine there is no grub option , it is immediately go to standard ubuntu

[zvacet]

Press shift key ( or is it alt,sorry I forgot) and you should be able to see grub.

[forsubhi]

thank you I still pressing shift and the grub appear

thank you very much