Last week my windows 7 operating system crashed. So I installed Ubuntu 10.04 on the partition Windows 7 was previously on. I have two Partitions, C: and D:. In partition D: I have very important data and I can't format it (I can't backup because it's very heavy ~50 GB). Now I want to install Windows 8. I have downloaded the ISO file of Windows 8 Pro. I don't have a DVD writer or a USB device to Install this. I need to install this on C: partition (the partition on which I have already installed Ubuntu) and I need to protect the data in partition D:. How do I do this?