I was using windows 7 32bit then it was showing some problems so I switched to Ubuntu and I accidentally deleted all my files on the hard disk during the Ubuntu setup....all those collection, pictures, videos and projects I had in my life is lost! Plzzz HELP ME!!!
I am so sorry. If you wiped and reformatted your drive, there is no way practical way outside of a laboratory to bring that back.
If it's any consolation, it's happened to each and every one of us at least once.
Best idea is to be very careful when installing a new operating system, and/or to keep extensive backups. Use two hard drives - one for media and documents, one for your system software and applications - is also a good idea.