Girls Aloud singer Sarah Harding celebrates her 27th birthday today and to mark the occasion we're taking a look back at her style. Sarah first burst on to the scene in 2002 when she was just 21 and her girlband, Girls Aloud won Popstars The Rivals. Back then (far left) Sarah wasn't quite as stylish as she is now with long platinum hair and a heavy fringe. Over the years her hair has got shorter and her dress sense has certainly improved. See below for a gallery of Sarah's style, take PopUK's quiz on how well you know her, and join us in wishing her a very Happy Birthday!