I would ditch Windows Defender and pick up a free AV. Either Qihoo 360 IS (not TS), Avast free, Avira Free. Any of these are better than Defender. Also adding HTTPS everywhere to chrome. Other than that you could also add Sandboxie free and run your browser in it. Other than that weekly scans with Hitman pro and Malwarebytes should keep you safe. Enjoy!