Windows vista wont load past microsoft corp loading screen?

Help! my computer froze and the mouse wasnt moving so i shut it down and turned it on. the screen wouldnt project at all even though i heard the sound. i had to unplug the vgi core and plug it back on. the screen appears on and then it did some kinda 3 step c disk check. after that it froze on desktop again and i restarted. this time, it wouldnt load p microsoft corp screen with screen bar. i waited forever. i tried starting it in safe modes but it gets stuck loading the .sys file idk wut to do at all i heard bout bios mode and that could be the problem but idk how to use it. plz help!!! thnx i have a gateway pc