Have a Sony VGC-RB60 Series PC. Got back from

Try the booting from the windows cd and repairing the os? if not working you may need a fresh install which means you will lose your data but your pc will still work. You can always download from www.ubuntu.com and burn the os to a cd rom and boot from cd, this will load a verison of linux, When cd rom starts chose RUN LIVE CD, this will not change the pc at all, when the os starts up you can go to places at the top and go through all your windows files and save the ones you want to keep to cd or external hd, then reistall windows, or who knows you might love linux and enjoy something thats free :)