To start your PC look for a button on the Mini-Tower that says power(sometimes it doesn't say power so press the button that is most noticeable). Then on the screen a startup page will appear. Then (for older PCs) it will ask you to press F1, do so. Then on the screen it will say Windows 98, Windows 95, or what ever operating system you have on your CPU. To open a icon hold the mouse on a icon then choose open, or just double click on the icon. To find out about your computer go to My computer and right click and go to properties. Then a window will appear telling you about your computer. Shut your computer down properly otherwise a program called ScanDisk will check your computer for any viruses.