Comment 4 for bug 872669

> save using SAVED, SAVEDAS commands (…)
> file saved as .svg or Inkscape .svg do not carry the correct extension

Ah, could it be that you are trying to save your files into a path which has a dot or period ('.') in one of the folder names?

That's a known bug and tracked in
 Bug #408566 “Program won't save files without given extension on Win32”
 <https://bugs.launchpad.net/inkscape/+bug/408566>

> but not SAVEACOPY

Additionally, bug #408566 seems to trigger a cascade of failures: due to
 Bug #769725 “The save as dialog gives wrong directory on Win32”
 <https://bugs.launchpad.net/inkscape/+bug/769725>
it seems that
 Bug #805095 “no File->Save As... dialog box if previously opened a file from a USB drive”
 <https://bugs.launchpad.net/inkscape/+bug/805095>
was triggered (see comment #4 there) and none of the file dialogs showed up for you.

In this case, it could be possible to reset the Inkscape preferences (which store the directory opened last time for each 'Save' command separately):

1) quit inkscape
2) in the Explorer, paste this path to the inkscape profile folder into the address bar:
%APPDATA%\inkscape
3) and rename the file 'preferences.xml'
4) restart Inkscape: a new 'preferences.xml' file will be created with the default settings.

Until bug #408566 is fixed, I'd recommend to avoid dots (aka periods) in directory names you access from within Inkscape.