I couldn't find a thread with a similar issue to mine so here's my issue, sorry if I missed something completely stupid.

I booted from USB and installed Ubuntu on a separate partition to dual boot with Windows 8. The installation went fine and eventually it told me to restart..so I did. But when the computer starts up it just takes me straight to Windows 8
I've tried several times but it doesn't give any options. How do I Get to Ubuntu??

I've dual booted W8 before with XP, 7 etc. and it used to take me to a Blue Win8 screen and ask me which OS I'd like to boot..

What am I missing here??