Installation Ubuntu 14.04 on Sony Vaio Laptop deleted crucial data .. Please help

[Parminder_Ghai]

I recently installed Ubuntu 14.04 on my friend's laptop ie Sony Vaio . It was a fresh install and it deleted the previous windows 7 and all the data on it . My friend later informed me that he needed the data and he had no back up . Can I recover the data somehow ? Any suggestions would be considered helpful. Thanks

[fantab]

Try Testdisk and Photorec (http://www.cgsecurity.org/)
or
Mini tool (http://www.minitool-partitionrecovery.com/)

100% data recovery may not be possible as Ubuntu overwrote part of HDD