Removing and adding OS on boot menu

I had Windows 7 and Ubuntu(ie ubuntu inside windows[no separate partition]). I removed Ubuntu from boot menu. And I tried to uninstall Ubuntu from Windows but some error occurs. So I simply deleted the Ubuntu folder. Also when I removed Ubuntu from boot menu, boot menu with Windows 7 option appeared(I thought the boot menu would disappear, since only one OS.) So I selected "Reset BCD configuration" from EasyBCD, and all the OS list were cleared(ie Windows 7) and then added new entry for Windows. So after that, the boot OS select menu disappeared and Windows booted directly. But now again I tried to install Ubuntu(again inside Windows), I installed it from wubi.exe, and I need to reboot to continue installation, But UNFORTUNATELY now the dual BOOT MENU for selecting OS doesn't appear, Windows boots directly without any option for Ubuntu. So I cannot install Ubuntu.