My cousin's computer after about 4 months of good use just crashed one day while he was doing work on excel. Now, whenever I try to boot up the computer, I keep getting a blue screen that says acpi.sys is corrupted. Thus, I reformatted the computer and tried to install winxp but after all the installation files r copied to the hard drive, it keeps saying that acpi.sys is corrupted and installation cannot continue. Does anyone know why? I even updated the bios to the newest official one and tried again. Same error. I then turned off ACPI AWARE OS to NO and I still get the problem. Does anyone know what's wrong?