i think ur PC drivers got outdated..may be that's the reason u r not able to hear music..update ur drivers by this application named Advanced System Optimizer..its utility Driver Updator..helps u in downloading latest drivers required & available on net for ur PC.
And do scan for spyware i think it also affecting the registries..so try its other tool System Protector gud for spyware protection.
Go into device manager (press start and type device manager) and press enter. Then scroll down to sound, video and game controllers. Press the triangle next to it and something should appear underneath. Right click on the item that has appeared underneath and click properties, then click the driver tab. Post back what it says from the top upto the buttons.
If it says windows provided the driver then the manufacturer may have a specific driver.
Some time driver CD doesn't install automatically Sound diver only. In this situation when you restart your PC,Your system automatic give popup for update. Then click automatically installation Process.
After This check My computer -> Properties -> Hardware -> Device Manager Properly install or not.
Don't install forcefully.otherwise you will have format.