My system is windows 8.1. From sometime ago, it starts to freeze irregularly at start-up during reboot. Screen shows 2 spinning dots and freezes at the windows logo screen. Turn off the PC and turn on could fix the problem in 80% chance.
I replaced memory but it doesn't fix the problem.
UPDATE:
I have 2 physical disks. One installs Win 8 32 bit, and one installs Win 8 64 bit. Both have same problem. Also, I try to boot from USB which has win 8 install file, it also freezes at 2 dots. It means unlikely disk error. Could it be power or motherboard problem?