Dell Inspiron 6400 Black screen problem

Hello,
Hello Dear,

I have a Dell Laptop Inspiron 6400 approx 5 to 6 years old. I had RAM and Hard disk upgraded last year with the good quality product.

Laptop was running perfectly since Saturday night. I clicked on “Install update and shutdown” on that day. When I tried to turned-on on Sunday Evening it shows only blue screen!! The process was on and I can hear the background music of processing and loading the programs.

I tried to reboot by pressing F8 and turned it on in safe mode but it remains on for a short time. I tried to perform system restore to several days back and was successful but then after a short time the screen goes to blank black from blue. I tried to remove the battery and cut off power and then again turn on with power cable but no improvement. I can hear the music and I can see the screen is also light up but it remains blank i.e. light black.

When It was turn on I tried to update the anti virus software but it was too slow and not completed. i.e. screen goes to black before completion I have to press power button to turn off computer.

I have window vista premium.

I can not see login screen or any icon on the home screen.

Is there a problem with software or hardware? Video card or RAM? Or any registry or update or virus problem?

I want to turn it on. I am desperately looking for some help to resolve the issue. Please suggest me some way to repair my hubby as I love this laptop very much.

Thank you very much in advance.

Nisarg