Files missing after installation

I installed Gallery 3 Alpha 2, and the installation was successful. However, I cannot add a photo because there is no 'browse' button, only a finish button. Also there are many 'page not found' errors. The Admin directory does not exist under the Gallery folder on our server. Example of error follows:

Page Not Found
The requested page was not found. It may have moved, been deleted, or archived.

kohana/core/Kohana.php [787]:

The page you requested, admin/modules/index.php/admin/recaptcha, could not be found.

Stack Trace
core/controllers/admin.php [46]:
Kohana::show_404( )Admin_Controller->__call( modules, Array
(
[0] => index.php
[1] => admin
[2] => recaptcha
)
)kohana/core/Kohana.php [270]:
ReflectionMethod->invokeArgs( Admin_Controller Object
(
[theme:private] =>
[uri] => URI Object
(
)

[input] => Input Object
(
[use_xss_clean:protected] => 1
[magic_quotes_gpc:protected] => 1
[ip_address] =>
)

)
, Array
(
[0] => modules
[1] => Array
(
[0] => index.php
[1] => admin
[2] => recaptcha
)

)
)Kohana::instance( )kohana/core/Event.php [209]:
call_user_func( Array
(
[0] => Kohana
[1] => instance
)
)kohana/core/Bootstrap.php [55]:
Event::run( system.execute )index.php [61]:
require( kohana/core/Bootstrap.php )