1. Reboot the computer and start tapping the 'F8' key before the Windows logo appears. Use the 'arrow' keys to navigate to the 'Last Known Good' entry in the menu that appears. Press the 'Enter' key to apply the setting and reboot. If the computer does not boot, then proceed to the next step.
2. Insert the Windows 7 installation disc into the CD/DVD drive and then restart the computer and press the 'Enter' key when the 'Press Any Key to Boot From CD or DVD' message appears. Click on your preferred language options in the 'Language to Install,' 'Time and Currency' and 'Keyboard or Input Method' drop-down menus. Click the 'Next' button. Select the 'Repair your Computer' link in the 'Install Windows' window.

3. Select the Windows 7 operating system entry listed in the 'System Recovery Options' window. Click the 'Next' button. Select 'System Restore' to start the 'System Restore' utility.
4. Select a restore point from the options displayed that have a date listed that is prior to when the system crash occurred. Click the 'Next' button and then click the 'Finish' button.
5. Click the 'Yes' button in the window that appears, and the System Restore process will start and then complete by rebooting the computer.
6. Click the 'Close' button in the 'System Restore' window that displays after booting to complete the System Restore process.