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Could you please add some system specs to your profile? Just lettings us know that you have 7 HP 64 doesn't help us finding an answer that much. Do you get any error message (saying other than just Windows Could not complete installation)?
You're also telling us that you're doing a clean re-install of Windows; I assume Windows has worked properly before? If so, which version? And what's the reason you're attempting a re-install? Hardware issue? Slow performance?