First, go out and get a USB disk bigger than the laptop disk, and use a live CD to copy a disk image of the laptop to the USB. That way you can experiement and

First, go out and get a USB disk bigger than the laptop disk, and use a live CD to copy a disk image of the laptop to the USB. That way you can experiement and write the original back if it doesn't work. If you had a dual install, the Ubuntu partition may not have been touched yet. However the partition table itself may have been overwritten. There is a free software tool called "gpart" that guesses the correct partition table based on the data on the disk, it may get you half way there, in that you can mount the linux part of things. For the windows part of things, the Asus CD probably started writing near the start of the partition, so you won't be able to reconstruct that. Lucky for you, all the user data is probably back a bit in the partition. I think I would try the tool "foremost" which is free software from the US Air Force's Forensic labs, to try to recover the windows files (and the linux, if gpart did not get you to a mountable partition). As for your business idea in retrieving lost partitions and data, it has been done, but I'd like to suggest a better business idea: backups.