Why does a pc restart automatically, ram seems good, hard discs have been swept by AVG and Avast Pro. Power source is OCZ stable and tested.
System is seriously unstable and reboots within a few minutes sometimes. Managed to install new updates but when I go to restart it doesn't load properly and beeps annoyingly. No overclocking of CPU.
On boot it states that computer is in safe mode, and recommends alteration of voltage in CMOS.
Computer was stable for 2 years with no issues. No upgrades of any hardwar only microsoft updates.
What are the recommended steps I need to take to sort this out, and what are the plausable causes considering the abovementioned?