I agree with everyone else, so I won't repeat what they've told you. However in addition to all that the easiest thing you can do right now is open up a checking and a savings account. When figuring out your credit score, how many bank accounts you have and the standing they are in contributes to your score. It is a very positive factor on your credit report as long as you aren't overdrafting or in the red. So open them up, put money in each, and don't bounce a check. Most likely, this will not build credit fast enough to get that computer by next month, so I'd ask mom and dad for that one.

Have a nice person add you as an authorized user. Preferably, this person will add you on a credit card with a huge limit and a pristine history. This is how people establish credit, well before 18, which is the legal age to enter into contracts and agreements and apply for credit.

Essentially, the information will be reported to the credit agencies, and it looks impressive if someone very reputable is entrusting you with the authority to use his/her card.

Building a credit score means they trust you enough to borrow money. Instead, I would buy it in cash. Save your money so you don't have to borrow money. Get a job and earn money. In the mean time, use a library's computer or friend's computer. Actually, most schools have computer labs you can use.

Co-sign, co-sign, co-sign. You can go to a bank and co-sign a small personal loan with a parent (assuming they have o.k. credit). You could go through a rent-to-own company, sometimes requiring credit, sometimes not. If you go into the store with a parent, you can get the Best Buy card cosigned with them, I'm pretty sure. Good luck.

Get a job. make money. get a secured cc. keep working. Pay off your cc debts on time, and preferable in full, and over time you will establish good credit and get an unsecured card.

Or have your parents buy it, since they want you to concentrate on college instead of being diverted by work.