I installed Ubuntu 11.10 on my desktop in Local Drive D as Local drive C was already having Windows Xp. I chose something else while installing Ubuntu and formatted with ext3 and chose use as '/'. But i didn't chose any partition for swap. Now when i rebooted the system after unplugging my USB, I found no boot menu offering choice between Windows and Ubuntu.Simply windows starts up. Moreover now i can't see any Local Drive D on Windows.However, using my bootable pendrive I were able to use Ubuntu directly from USB and can find Local Drive D & C (both with new name "21 System File") there with Ubuntu files loaded there.
So now how can I switch between Ubuntu and Windows and find Local Drive D on my Windows.