Boot Up problems

Hello,

My school has provided me with an Acer Laptop which has been mine since the start of last year. I have this problem where it will not boot up past the first image seen on the laptop. I remember it has done it before and I had fixed it but I do not know how, and I believe that I myself would rather not try fixing it with no help whatsoever. I wouldn't trust myself. It's quite stressing and will not be at school for them to repair it for another week and a half, and when I arrive I cannot afford to arrive empty handed... Please help me, anybody :( I'm desperate!