Try going back to an earlier restore point. The option to restore to an earlier saved stable operating system can work .. you should find it through the control panel.
If not... You can try repair windows.. ie boot via your windows cd and attempt a repair.
I'd say try reinstalling the drivers for the laptop re the internet/ethernet, etc via another pc and reinstall them... but it sounds like it's too far gone for that.
Format and reinstall windows via your windows cd is probably the best idea.
(ocultar) Si deseas jugar una partida contra un adversario de nivel similar, puedes definir en tu invitación de nueva partida un rango BKR apropiado a tu interés. En tal caso, nadie con un BKR fuera de dicho rango podrá ver o aceptar la invitación. (Katechka) (mostrar todos los consejos)