Follow the below steps it would fix your issue.Method 1: First you need to try safe mode and check if you
are able to boot to the desktop.
Follow this below
provided link to start your computer in safe mode.Advanced
startup options including safe modehttp://windows.microsoft.com/en-US/windows7/Advanced-startup-options-including-safe-mode Method
If you are able to boot into safe mode then in order
to troubleshoot this issue further, you may unplug all the external
devices except keyboard and mouse and check if you are able to boot to
the desktop. Method 3:
If the above provided
steps don't resolve the issue then, I would recommend you perform
Follow these steps: To perform a
Startup Repair follow the steps below:
a. Please insert
the Windows 7 DVD and reboot the computer.
b. When we are prompted
to press a key to boot from the DVD, please press Enter or the space
c. Choose your language settings, and then click Next.
Click Repair your computer.
e. Select the operating system you want
to repair, and then click Next.
f. On the System Recovery Options
menu, click Startup Repair. Startup Repair might prompt you to make
choices as it tries to fix the problem, and if necessary, it might
restart your computer as it makes repairs.Access the link below for more information about startup
repair:Startup Repair: frequently asked