did a fresh windows install on new drive, performed all windows updates, left it overnight. frozen by this morning.
gonna try this again with an xp install same disk tonight.
didnt do the xp install. ended up taking it to the techs where i bought the components. They troubleshooted hardware with the tools i didnt have, swapped RAM, tested PSU, HDD etc and no hardware faults found.
Disabled PLL overvoltage setting in BIOS and reset all other settings to default. They said that was the issue however upon reconnecting up back at home it froze randomly like it had been doing before. Ran Prime95 and Furmark all night for 8 hours, no issues found. Ran Intel CPU test utility. No issues found.
I disabled C3 Reporting and C6 Reporting settings in Advanced -> CPU settings in BIOS and this seems to effectively stop the ranbdom freezing. However this also disables CPU throttling and it stays at full clock speed while running.
Also updated AMD HD audio driver with the correct Realtek HD Ati driver. W7 automatically updates it to AMD which is incorrect.
Tech also mentioned the possibility that having lots of other stuff plugged into the wall outlet could lead to power issues. Currently installed UPS to see if this improves anything and re-enabled CPU throttling. Will report back.
Also going to contact ASUS as I am starting to think this issue is in fact related to power supply gremlins due to other large draws on my available outlet which are affecting the motherboard and the throttling of the CPU to improve energy efficiency.
My PSU should be more than sufficient for my rig so I'll wait and see if the UPS helps any and what ASUS has to say.
EDIT: Re-enabling C3 & C6 CPU throttling function leads to freezing again.