Can my hard disk be interrupting my wifi connection in laptop?

edit

I had been facing the same problem and as suggested in the above answer yes it was USB 3.0 who was interfering with the WiFi signal. Simply ejecting while using the internet worked for me. In my case it was blocking only the 2.4 GHz bandwidth, just check if the same is the case with you. So if you necessarily need the internet while the hard disk is still connected then you can use the 5 GHz bandwidth.