[why does my viewer flash off and on]

when i open any viewer, SL, Phoenix or Firestorm, the viewer flashes off and on about once a second and it is driving me crazy. Almost to the extent of stopping SL and I love it. can anyone help me. it happens even when not connected to the internet so it is not a server issue. AND since it happens on all viewers it must be a video driver or computer problem. I am running windows 7 home premium 64 bit and i have a NVIDIA GeForce 7050 card. I have 750GB on the  hard drive and 4GB DDR2 memory. the problems started when i used a driver update service to update all my drivers. I hope someone can help me.

[when i open any viewer, sl or phoenix or firestorm the screen flashes off and on]

when i log in to second life with any viewer  the screen flashes between the viewer and my desktop. I think it may be a problem with my video card but I have updated the card to the latest drivers. I am running windows 7 and have an Nvidia video card. I did not have a problem till i updated the driver. any help please