Too bad! 40 1

Hello,
Delays were required (as always with Amazon), the parcel was in good condition and the start seemed suitable.
Except that no document to guide the installation, no information on how to begin.
The keyboard, though installed did not work at first, then began to run, then stopped again, although I have a clue about what I could do for these changes.
Windows 8 Knowing the system does not scare me, but from the outset: "Windows explorer has stopped working." I uninstalled the antivirus Mac Afee and installed Avast, IObit Uninstaller and Google Chrome. And always "Windows explorer has stopped working" nonstop.
Unable to stop the computer or do anything else.
Then I was offered to restore the computer, which I accepted, until I'm facing a paid site for a computer that I had just received (only one hour) and was left desperately blocked .
So I asked to return the unit