Associate
Whatever happens, you will be solely responsible for the repayments...
This. If you get the loan and your mate can't pay you back then you may end up with a bad credit rating yourself (e.g. through late or defaulted payments) or have to pay off his debt for him.
You could always draft some sort of agreement between you so that the loan is secured against the PC (e.g. the PC is actually "yours") and must be returned to you if repayments aren't made. It would become "his" once the loan was repaid. Worst-case - if he did default then you could always sell the PC to recoup some of the cost of the debt repayments.
