1) Would be helpful if you identified your system, Primarily the MB.
2) This is often a case of:
.. A) An BIOS problem that may be resolved by updating your BIOS to the latest revision.
.. B) Incorrect setting in Bios for the HDD. Installation should be done with the BIOS set to AHCI and ALL other HDDs disconnected.
.. C) A hardware problem:
...... Bad DVD, or Problem with DVD drive reading.
...... Memory errors. Should ALWAS verify (even on a NON OCed system) that memory is not producing memory errors. Can do this by down loding memtest86 and create a bootable CD.
Ref, SEE: http://www.memtest86.com/
NOTE, You do not need to Buy cd Just down load the ISO. DO NOT just copy this file to a CD, use the ISO function in CD/DVD writing program. Normally if you drag the file to the DVD drive (in My computer, the correct method for creating a bootable CD will be selected.