No disrespect intended, Tigger, but considering that you have admitted that you don't know your A from your Elbow and have had trouble with both Firefox and I.E., I would kindly suggest that the main problem is YOU.
You wouldn't expect anyone to diffuse a bomb without some instruction, would you? but many people go to Comet, buy their first laptop and then wonder why it all goes wrong when they get it home.
I would suggest that you get your brother or some one else to give you a few lessons on what to do and, possibly more importantly, what NOT to do.
There are plenty of free lessons/computer classes available at libraries etc.
I hope you soon get your computer sorted out but I think it will be by the personal hands on approach.
Good Luck.