Go the link below, download all drivers needed, and install on your system. The device manager should not have any error on any entries there, so your system will work properly.
http://esupport.sony.com/US/perl/swu-list.pl?mdl=PCGK23&LOC=3
Your laptop have network NIC:
http://esupport.sony.com/US/perl/swu-download.pl?mdl=PCGK23&upd_id=1444&os_id=7
And also wireless:
http://esupport.sony.com/US/perl/swu-download.pl?mdl=PCGK23&upd_id=1535&os_id=7
Those 2 should be installed so you can make sure network devices working before setup network and access internet.