I have lenovo laptop. I installed first windows 7 on a 60 GB partition. Also I had an empty 400 GB partition with ntfs formatting. In the remaining disk space I installed Ubuntu 13.04 Gnome edition and a 2 GB swap-partition. After installing Ubuntu I restarted and instead of showing any GRUB menu it directly boots to windows 7. I tried to boot from the live CD and checked that the Ubuntu is already installed. I tried the chroot command to access the installed Ubuntu from the live cd and tried install-grub and update-grub. They worked fine. The update-grub command showed all the three entries for Win 7 and rest two for Ubuntu. But when I restarted nothing showed up and I booted directly to Windows 7.
Please help me to get GRUB menu. I've tried re-installing Ubuntu but it didn't help.