10.13 High Sierra Problème réinstallation MacOS bloqué

[kor-o]

Bonjour j'ai un problème avec mon iMac (date 2011)
J'ai voulu ré-installer High Sierra car par erreur j'ai transformer mon compte Admin en standard et je me retouve bloqué à macOS Utilities. Impossible de ré installer sur le disc, il est vérouillé et je suis perdu avec le terminal.
Quelqu'un aurait une solution?
Merci


J'ai tester "diskutil list" voici le resultat :

-bash-3.2# diskutil list
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                  Apple_HFS OS X Base System        999.3 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3

/dev/disk1 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +5.2 MB     disk1

/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk2
   1:                        EFI EFI                     209.7 MB   disk2s1
   2:                  Apple_HFS OS X Base System        999.3 GB   disk2s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk2s3

/dev/disk3 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +524.3 KB   disk3

/dev/disk4 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +524.3 KB   disk4

/dev/disk5 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +524.3 KB   disk5

/dev/disk6 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +2.1 MB     disk6

/dev/disk7 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +524.3 KB   disk7

/dev/disk8 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +524.3 KB   disk8

/dev/disk9 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +12.6 MB    disk9

/dev/disk10 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +2.1 MB     disk10

/dev/disk11 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +1.0 MB     disk11

/dev/disk12 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +2.1 MB     disk12

/dev/disk13 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +524.3 KB   disk13

/dev/disk14 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +524.3 KB   disk14

/dev/disk15 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +1.0 MB     disk15

/dev/disk16 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +6.3 MB     disk16

/dev/disk17 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +6.3 MB     disk17

/dev/disk18 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +524.3 KB   disk18

/dev/disk19 (disk image):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               +2.1 MB     disk19

-bash-3.2# diskutil cs list
No CoreStorage logical volume groups found
-bash-3.2#