Black screen after being hacked for: OS edition info, Purchased - Microsoft Community

i computer tech working on client's machine brought in black screen movable cursor. 

first thought virus or malware.  pulled drive out , put drive reader.  scanned virus, malware found none. ran chkdsk /r

and there 4 files chkdsk did with.  files had strange characters  0-fileassociation etc.

i searched dat files on system , found

0-get os edition info

0-get purchased list

1-start service

2-get genuine ticket 

and bunch of lines started 4- had winstore.  there 113 lines of code.

i deleted 0-4 dat command lines.  hopeful. replaced hard drive , powered on.  hp logo came , circle made of dots showing, have nothing black screen.

i cannot windows clean boot.  cannot safe mode.  , scanned drive while in drive reader , found no malware or virus on drive.

it seem hacker entered, got wanted, , left.  file associations have been erased.  client has no restore disks putting disk in reader show restore partition.

could me next step?

ps child using computer, playing minecraft... adults have issues.  developed after child installed minecraft...

right pew, wrong church. post here instead => https://social.technet.microsoft.com/forums/windows/en-us/home?category=w7itpro

Windows / Windows 10 / Windows update, recovery, & backup / PC