system taking hell lot of time to start

[jaishankar]

My desktop is celeron 2 ghz with 1 GB Ram its 845 chipset motherboard, in the past i had a Mother Board which i got from the person from whom i purchased from, and it was fine, once my frnd bought a 4 GB Ram and i tried it on my Mother Board, out of know where their was a smal burn on my Mother Board, which was not visible to the naked eye and the service person couldnt repair it and i had to go for a new one, as celeron Mother Board are not available in the market i had to go for some low cost Mother Board like Millenium, at the begining the installation was good as time passed it started creating problems, if i shutdown my computer it takes atleas 4-5 min to start, so i never shut it down always hibernate it, which is much faster than shutting down, and when i try to install the OS, the screen of preparing to copy files the next screen appreas after 10-15 min or some times more like 30 min, thats why i created a backup using Hirens boot CD and restore it when i need to format the PC, could anybody guide me what could be the problem, is it the problem of BIOS or display, and some times when i play a video song say in MKV format the screen goes blank and after few minutes a message appears system VGA has encountered an error, plzzz help me