Maya3399 :
I was using Win 7 But i install Zorin & I open my Pc then i see there 're no drive & No files.Which is very important for me .
How did you install the new operating system? If you don't know what you are doing and don't read the prompts you can easliy have over-written your files as a clean operating system setup would have formatted the drive then installed the new OS clean.
Remove the hard drive from the computer plug it into a secondary one and use a file recovery program like Recuva to see if it will find any files it can copy that were deleted when you installed the new operating system.