gnuwin32 wget Unable to locally verify the issuer's authority

I have just installed gnuwin32 wget and have had some issues when ruing it. I appear to have issues with https sites... I get a "Unable to locally verify the issuer's authority." error. I have very little knowledge of this kind of thing, searched for answers on Google and went round in circles. The sites I found had cert checkers that said my certs were OK, is it my certs or the web site that's an issue.

Thanks Stevo