COMPUTER QUESTION! Think it may be hard drive? Toshiba laptop, brand new, Windows XP...?

COMPUTER QUESTION! I have a Toshiba laptop. A few days ago, I went to turn it on, and it would get to the screen where Windows XP was starting up, but it would never open windows actually. It brings you to a black screen with white/gray type saying an error occured and Windows cannot open, etc. Then it says 3 options about midway down, I believe the first option is safe mode, can't remember others at moment. But then it has an option to use last good configuration known or to start windows normally. We had same thing happen to our desktop a while back and it was the hard drive. They took me through steps over the phone to try and fix it, but it didn't work so we ended up bringing it to a repair shop, and it sat there for 1 whole month. Long story short, I am wondering if anyone can tell me what to do to try and fix it? Even if I have to reformat the whole thing. I do work on my computer and need it back up, WITHOUT having to have it sit at repair shop for a month again! THANKS!