I was confused about memory support, Biostar P4M890-M7 TE only support DDR2 400/533 only. But, previously it using 667 memory without problem. So, I should using 533 memory or 667 memory? Because 533 memory now rarely sale.
If your board was able to underclock the DDR2-667 memory, then using the 667 memory that has the same specifications should not cause problems even though it doesn't support the higher frequencies. Just make sure that it has the proper voltage for your board and it should work. If 533 memory is not an option for you due to poor availability, then the 667 memory is your next best choice. Like I've said, just keep in mind that it is being treated as 533 memory and you're not getting any performance boost compared to 533 memory except maybe in slightly lower latencies.