I have installed Ubuntu as a dual boot with Windows 7 following the step on the installation. Ubuntu works fine, and Windows 7 appears as an option on the boot menu, but when selected, hangs. I was concerned to see files from my windows installation appearing in a Device called OS in the file manager. Have I lost everything? or is there some way back?
You just have messed up the MBR of windows. Just try to put a window DVD or USB(window setup on it) and start a system repair and fix the MBR of windows by the command at system repair:
this command also worked for me to get back windows:
After that, you have to reinstall the grub loader. Just try a live CD of ubuntu and open terminal and write:
Now You can dual boot both operating system properly. For me it worked well.
and from there you can come up to know the partition of the window