Been having this issue quite a bit, play a little GW2 for a while, then suddenly PC turns off. Can be for just 20 minutes or for 8 hours. The timing seems odd. Used to think it was caused by Chrome, as I would have a large number of tabs open when it occurred. Past few times that has not been the case.
Specs:
Windows 7 professional x64
AMD FX-6100 3.3ghz (no OC)
GA-970-D3 Mobo (8/31/2011 BIOS version, noted as stable for GW2)
32 GB Ram on sticks and another 32 GB as paging (old habit to set it that way)
AMD Radeon 6850 (1-10-2013 version also noted as stable for GW2)
PC and Ram stress tests ran a week or so ago, 12 hours straight for each one, no issues.
Tried turning off cores on start up, issue still ocurred.
Temps (from speed fan 4.49, all temps in Celsius prior to starting GW2);
Temp 1 – 36
Temp 2 – 37
Temp 3 – 32
HD0 – 33
GPU – 40
Temps after running GW2 for 1 hour
Temp 1 – 37
Temp 2 – 56
Temp 3 – 63
HD0 – 32
GPU – 59
HIgh yes, but I’ve had those temps in the high 60s and low 70s and didn’t have my computer turn off.

