I have Windows 7 Home premium 64bit installed on my laptop, Now I have installed Ubuntu Desktop 13.04 from bootable flash but Ubuntu GRUB menu not showing.
When I start my PC, after normal boot, there is no GRUB or OS Selection menu and my system loads straight into Windows 7.
I selected "Install Ubuntu alongside Windows 7" then from "advance partitioning tool" I selected different drives for Ubuntu
If I run Ubuntu installer again it says you already have Windows 7 and Ubuntu 13.04 on your system.
I read it in ubuntu help that
In the drop-down under Device for boot loader installation:
Never choose any other partition! (this may break the boot of your other systems Bug #1049549)
see img here
So i deleted my / drive and installed ubuntu again with this configuration, its working fine now. Thanks to all for answering.