windows 7 screen flashes at log in screen.

Hi rupesh_b007,

You may try using your system in safe mode with networking and see if it exhibits the same behavior by following steps below:

• Restart the computer.
• Tap the F8 key on the keyboard during the boot process until you see the Windows Advanced Options Menu on the screen.
• Select “Safe Mode with Networking” from the menu using the arrow keys on the keyboard and then press the key.
• Select the user account at the log in screen.
• See if the system issue exhibits the same behavior. 

Another step you may try is to uninstall video drivers from 'Device manager' and re-install it by following the steps below:  

• Click on “Start” and right click on “Computer”.
• Click on “Manage”.
• Click on “Device Manager”.
• Under “Display adapters”, you will find the video driver listed.
• Right click on it and click on “uninstall”. (Check and make a note of the driver installed on your system and re-install the driver from the below steps accordingly).
• Check the box to delete the software.
• Restart your system and click on the link: http://dell.to/QjjZDA
• Enter the Service Tag of your system and select the operating system.
• You will find the video driver under “Video”.
• Click on the video driver depending on the video card your system has. (Install the same video driver which you uninstalled from “Device Manager”.
• Click on “Download File”.
• Select “For Single File Download via Browser”.
• Click on “Download Now”.
• Save the driver on your desktop.
• Once the driver is saved on desktop, right click on it and select “Run as administrator”.
• Install the video driver by following the on screen instructions.
• Check if the issue is resolved or not. If the issue still persists, update the system BIOS.

Note: Make sure the ac adapter is connected and the battery is charged 10% or above to update the BIOS. Also, disconnect all the external peripherals before updating the BIOS. All the programs should be closed and documents saved. 

• Click on the below link: http://dell.to/QjjZDA
• Enter the Service Tag of your system and select the operating system.
• Go to “BIOS” and click on the BIOS available.
• Click on “Download File”.
• Select “For Single File Download via Browser”.
• Click on “Download Now”.
• Save the BIOS on your desktop.
• Once the BIOS is downloaded on the desktop, right click on it and select “Run as administrator”.
• Follow the prompts on screen and restart your computer.

Please share the findings.