No icons

Hello,
i just got the same problem that many of you are having. i can only open thru task manager. i've tried finding windows , but nothing comes up. i have three students at home, We desperately need this computer to work.
can some one give me an idea of what i can do? i can open internet, desk top, and some files, but no icons and no start botton. please, help i can't use the recovery disk cause i don't have it. besides that i can't lose the power point program which the kids need. help, thank you, mari, Miami, FL