The ACPI_BIOS_ERROR bug check has a value of 0x000000A5. This bug check indicates that the Advanced Configuration and Power Interface (ACPI) BIOS of the computer is not fully compliant with the ACPI specification.
Your stop error points to BIOS. you probably haven't done anything to the BIOS though. The issue could be hardware. Is the computer under warrentee or purchased at a store that can test it out for you?
More info on this error: http://support.microsoft.com/kb/314830
When you are installing Windows XP, you may receive the following Stop error: STOP: 0x000000A5 (Parameter1, Parameter2, Parameter3, Parameter4)
The ACPI Bios in this system is not fully compliant to the specification. Please read the Readme.txt for possible workarounds, or contact your system vendor for an updated bios.
The bios in this system is not fully ACPI compliant. Please contact your system vendor for an updated bios. If you are unable to obtain an updated bios or the latest bios supplied by your vendor is not ACPI compliant, you can turn off ACPI mode during text mode setup. To do this, simply press the F7 key when you are prompted to install storage drivers
. The system will not notify you that the F7 key was pressed--it will silently disable ACPI and allow you to continue your installation."