RE: unable to connect to any wireless connections

Hi, I have a Dell Latitute 3550. Computer was working fine this morning, until the battery went low. I plugged it back in and now it won't connect to the wireless internet. Internet connection is fine on other devices. I get an error message that no wifi connections are available, this is not true but nothing is showing up. I've tried restarting it and just completed a system restore to no avail. 

Any suggestions on how to resolve this?

Many thanks in advance.