Unable to download and install updates

Every time I try to install new updates I get that my computer isn't connected to the internet.

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 8.1, 64 bit
Processor: Intel(R) Core(TM) i5-4200U CPU @ 1.60GHz, Intel64 Family 6 Model 69 Stepping 1
Processor Count: 4
RAM: 12200 Mb
Graphics Card: Intel(R) HD Graphics Family, -2016 Mb
Hard Drives: C: Total - 944278 MB, Free - 866132 MB;
Motherboard: TOSHIBA, VG10ST
Antivirus: Windows Defender, Disabled