hi friends.last day i was working with windows vista and then restart my system and nothing shown on the start up just a black screen.i turned off system and on it again but still no picture on the screen. i changed my video card(geforce 6200 256mb agp) with geforce 5200 and it booted.
then i changed it again and nothing came up.i did this several times and suddenly my system booted normaly. i ran windows and everything was ok.
i restarted my system ,same problem again!!!no boot up screen just black.
i dont know whats the problem really my motherboard or graphic card.
my system works properly with 5200.