centering tiagra front brake

Just dug my road bike out after a number of years in storage and have noticed my front brake is constantly rubbing on one side of the rim. I have tried adjusting the small screw at the top of the calliper but this doesn't seem to resolve it. When I remove the wheel the brake seems to sit at an angle as opposed to being relatively straight. The only way I can currently ride is if I completely slacken off the front brake but then I have virtually no braking at the front. Any ideas how I can fix this?