Blinking lower part of the screen (under the taskbar area)

Yesterday my laptop got infected with a virus. My Norton Antivirus 16.8.0.41 didn't detect any threats when i ran the system full scan. However my norton  got disabled shortly after that, by the virus (though I still have 90 days of subscription left). Norton Live update is no longer opening. I get warnings that my definitions are outdated and that norton faced an internal error.

 

Observation:

 

I get an annoying flashing in the area near the taskbar every 3 to 4 seconds, This flashing is basically a reflection of the upper part of the screen. I am using windows 7. My problem is similar to that posted by another person on the following link:

http://www.youtube.com/watch?v=LrKM32ssnMA.

 

 Note: even when the computer is rebooting (before logging in) the lower strip of the screen is blinking.

 

Why am I getting this? How can I fix it? Are their virus definitons or tools to eliminate this virus? thanks