Sometimes you get a bottle of wine that is just "off". It doesn't smell or taste the way it should. I recently opened a bottle of 2007 Kim Crawford Marlborough Dry Riesling that I picked up in the bargain bin at a local wine store. Upon opening it I noticed an uncharacteristic and unpleasant odor. I tasted it just to be sure and yep, it's bad.
This is a screw cap wine. This kind of enclosure drastically reduces the frequency of "cork taint" or TCA. But the reality is that any wine can go bad and sometimes does. It might come from the winery (cellar taint) or just from being exposed too often to temperature extremes, or from leakage or any number of other reasons.
If you are confident the wine is bad, save the unused portion and return it to the wine store where you got it. Most will accept it back for store credit.
You can also choose to pour it out and open another bottle. If you're unsure the wine is bad, have someone else try it. You might
not care for the flavor (which is OK) but the wine may not be bad.
The important part is to not drink something you don't like.
Raise a Glass!