PC was working entirely yesterday, went to run today, no boot drive found, disc drive working. Checked bios and it cant see the hdd, tried hdd in other computer and it worked perfectly (viewing files, didnt try booting). Tried a different hdd in first PC and it didnt see that one either. Hdd seems to be clicking sometimes and not turning on other times when connected to first pc but sounds fine with other pc. Potentially a PSU issue?? Any ideas are appreicated