I would also like you to download the file below save it to your desktop unzip it there then right click and select merge thie file will set all of your services back to default in case something got changed.
Also please uninstall the program below.
UnThreat Free AntiVirus Installer (Version: 188.8.131.52)
Then download the windows all in one repair tool and run it as admin with all the boxes checked below.
Reset registry Permissions
Reset file permisssions
Register system files
Repair windows firewall
repair mdac/ms jet
remove policies set by infections
repair winsock and dns cache
Reboot your machine.
Now check your issue.
If all of the above fails then you might consider setting a static ip for this machine so that there is not any conflict with other machines in your household.