Computer won't start properly after forced shutdown

Ok. This problem comes with a little bit of a story.
About 2 days ago(though I don't think it's relevant), my little brother decided he wanted to go on the computer. He turned it on, and the relevant lights turned on. I looked away for a second, and when I looked back, he had pushed the power again, and held it to do a force shut down. The boot screen hadn't loaded, heck, it wasn't 15 seconds after turning it on he did it.
Now when I try to turn my computer on, the power lights up, and the yellow CPU activity light(i think thats what it is) flashes a few times, then just stops. I have once managed to get it to load, in which i got to the <F12> system bios like page, then just stopped. I have no idea where the problem is, and how to fix it. Any help would be appreciated.

PS. I don't have my system specs ready on me right know. i'll edit them in soon.

Laptop or desktop? The hard drive's boot record may be corrupt