I used to overclock my I7 2600K @4.2ghz. I have 16 GB 1600 Mhz ram. The other day my computer froze up. I was unable to boot up except when I when back to the fail safe options. I now run my CPU at 3.4ghz and ram at 1333 Mhz. Do you know what could of happen to cause this? Is my PSU going bad? Thanks.
OCZ 700 Watt
4 x 4 GB Ram 1600 Mhz
2 x GTX 670 in SLI
1 x 256 SSD
2 x 1 TB traditional hard drives.
Components naturally degrade over time. Overclocking degrades them much faster. 4.2 Ghz on a 2600K is not a particularly aggressive overclock and I would not expect it to be causing problems for you at this stage but it is entirely possible that the chip that you have will no longer run stably at that frequency.
Chips ship from the factory with a VID that ensures sufficient supply voltage to allow the chip to run stable through its warranty period and ideally long afterwards. Most overclocking guides have you find the lowest stable voltage and stick with it. Over time, electromigration and other forms of degradation will render this voltage insufficient, necessitating small bumps. Most people will replace overclocked chips long before they become unusable/unreliable, but some chips will simply wear out faster than others.