SublimeText3ContextMenu.reg

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\*\shell\Open with Sublime Text]

[HKEY_CLASSES_ROOT\*\shell\Open with Sublime Text\command]
@="C:\\Program Files\\Sublime Text 3\\sublime_text.exe \"%1\""

[HKEY_CLASSES_ROOT\Folder\shell\Open with Sublime Text]
@="Open with Sublime Text"
"Icon"=hex(2):43,00,3a,00,5c,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,20,\
  00,46,00,69,00,6c,00,65,00,73,00,5c,00,53,00,75,00,62,00,6c,00,69,00,6d,00,\
  65,00,20,00,54,00,65,00,78,00,74,00,20,00,33,00,5c,00,73,00,75,00,62,00,6c,\
  00,69,00,6d,00,65,00,5f,00,74,00,65,00,78,00,74,00,2e,00,65,00,78,00,65,00,\
  2c,00,30,00,00,00

[HKEY_CLASSES_ROOT\Folder\shell\Open with Sublime Text\command]
@="C:\\Program Files\\Sublime Text 3\\sublime_text.exe \"%1\""

This does folders as well as files, no need to check the box during installation, just use this.