A group of people have noticed at adslgr.com a problem while trying upgrading from Windows 7 to Windows 8. We couldn;t find the cause of the problem.
At the end we found that upgrading from Windows 7 to Windows 8, from greek (windows 7) to English (windows 8) is impossible. The problem is the...
Files, what files? If you mean Windows 8, you can download an iso file, burn it on a disk and then put this disk in your laptop's drive and boot from that. Then complete the installation.
It's the easiest way.
Windows 8 Release Preview ISO formats