Problem: 'ArcPad StreetMap' does not show up in the list of available extensions
After installing ArcPad StreetMap on a Pocket PC device, it is not listed in the Extensions page of the ArcPad Options dialog box, or in the About Extension list in the Help dropdown list.
The ArcPad StreetMap extension installs into the \Program Files\ArcPad\Extensions folder. If ArcPad was not installed into the default folder, which is: \Program Files\ArcPad, it will not be aware of the extension.
Solution or Workaround
Either reinstall ArcPad into the default folder or move the extension files into the Extensions folder under ArcPad's install folder.