OK, people. We usually work with enthusiasts of all levels of experience and skill. We forget that, for most PC users, a PC is a tool to get work done. And daltero's PC (tool) is broken. Everyone's suggestion assumes daltero knows more than he probably does. Most of the suggestions also assume that he has another computer available.
daltero, Here is what we think your problem is. You have a PC with bad Windows. Cannot load Windows. Schoolwork on it. No backups.
If you format the hard drive and reinstall Windows, you will lose your data files. All of the suggestions everyone made are ways to try to save your data.
The best thing for you to do is to ask someone at school for help. Anyone willing to help should know what to do. The simple thing to do is to open your computer, pull your hard drive, and install it in the other PC. Back up your data to CD. Make two backup CD's. Put your hard drive back in your PC. Now you can try to reinstall Windows. If you can install Windows without formatting the drive, Windows should your programs and your data. And if you must reformat and install Windows again, your data is safe on the CD's.
If you can not get help, go down town and buy the smallest hard drive you can. Make it the Master drive and your original drive the Slave. The dealer should be able to help. Install Windows on the Master drive. Use Windows to find your data on the other drive.
This is important. Your original drive may be failing. As soon as you can read from it, IMMEDIATELY copy the data somewhere else.
I hope this helps.
And you have also learned why backups are so important.