Windows 7 is by far the best OS to be released by Microsoft till date. When you install any software or drivers on Windows 7 or if any installation fails, it might cause issues with Windows 7 start up and this might effect Windows 7 booting. In case you encountered any such situation, best way is to repair Windows 7 using the DVD. Windows 7 DVD has system recovery tools to repair and recover issues with Windows 7.
To start repair, insert the Windows 7 DVD and restart your PC. Press any key to boot from the CD and Windows 7 will load the set up files. In the first step select the language and country and then click next.
In this screen select the option “Repair your Computer” as shown in the image. This will open up the system recovery options. You can either use the recovery tool to fix problems starting Windows or else restore the computer using a system image you have created previously without repairing.
Select the partition where your Windows 7 is installed and then click Next.
Here you can see the recovery options available. Startup Repair tool should be able to solve any issues causing Windows startup. There is also system restore or system image recovery if you have enabled these options previously. Once you have repaired Windows 7, you can restart the PC and login.