I own a Compaq Presario 5310US... it came from the factory with XP but I got a virus and the HDD needed to be re-formatted....I cant re-install XP cuz I dont have a disc....so I want to install 98SE since I have the disk and a key for it....when I start the PC it says invalid system disk...replace the disc and press any key to continue...and when I put in the 98 SE disk and press a key it goes into the Windows 98 SE setup disk menu and asks me to press 1 to boot from hard drive, and 2 to boot from CD....so I press 2.....or press down and enter....whichever....then it says: I/O error, replace the disk and press any key to continue.....what does I/O error mean, and how do I fix it so I can have a working PC.....thank you for your help^^