Disk Problem

Hello Guys,

I have MacBook Pro (15-inch, Early 2011)

I had OSX Lion and Windows 7 installed, but suddnely the Mac won't bootup on both, so i had to try to reinstall the OSX, but i am facing many Problems.

First i tried to reinstall Mac OS X 10.8 Mountain Lion with Utility Manager, but it says could not find Installation information for this machine, and sometimes give another error ( An Error occurred while preparing the installation, try running the application again )

Second i use Disk Utility to Erase the whole Disk, i got errors Dis Erase Failed couldn't unmounted Disk, i even unmounted both Macintosh HD and BOOTCAMP manually and erase itself but still getting this error, i tired another method by using Partition tab and create partition 1 still getting the same error partition failed couldn't unmount disk, even when i try to remove the two partitions from current it give me the same error couldn't unmount disk.

I used terminal method and tried all kind of commands still same

diskutil unmountDisk /dev/diskx

diskutil unmount force /dev/diskxsy

diskutil unmount force /dev/diskx

diskutil eraseDisk JHFS+ MacintoshHD diskx

last command ended up with error ( couldn't unmount disk error 69888 )

i am freaking out, i can not reinstall nor install fresh OSX nor recover

i even made First Aid and the disk good..

Please is there any solution ???!!!