I've got Ubuntu 9.10 installed in an NTFS partition. After an update, I started getting kernel panics, so I need to reinstall it. But before I do that, I need to retrieve and backup my home directory. I believe Ubuntu's file system is packaged in the root.disk image. So how do I mount it in Windows?
I don't know how to mount the / partition in Windows 7, but I would use an Ubuntu Live cd to boot and, within the live session, I would mount an external hard drive to do backup.
If you haven't an usb drive you could use the Ubuntu Live cd, then mount the Windows 7 disk and copy all your files inside that.
Hope that helps,