How to get rid of CKEditor and recover access to admin pages? I can't access anymore to many module's admin page (especially CONTENT : bueditor, wysiwyg, smileys. And MEDIA : IMCE or Imagepicker) since I uninstall CKEditor. I don't know if that's exactly linked but since then, when I go to admin/config/content/ I get "Advanced Forum", "Text Format", and "CKEditor" even if I've uninstalled it.

Of course, when I click on "CKEditor", I get a normal PHP error :

Fatal error: require_once() [function.require]: Failed opening required '*****/sites/all/modules/ckeditor/includes/ckeditor.admin.inc' (include_path='.:/usr/lib/php5') in *****/includes/menu.inc on line 501

BUT if I try to force access, like typing admin/config/content/bueditor or admin/config/media/imce, I'm redirected to admin/config/content/ or admin/config/media

P.S.: I'm on D7.
I have to ask, did you properly uninstall CKEditor?  As in disable the module first (in admin/modules) and then uninstall (admin/modules/uninstall)?

It sounds like you just deleted the folder without uninstalling it properly...