Most of that info was included in my original post, but OK....
Graphics Card: MSI Radeon R9 290X 4Gb
Catalyst Driver Version / History: 14.4, from clean
Operating system: Windows 7 64 bit, with all the latest updates installed
Issue details: As above, system completely locks up at seemingly random times, requiring a hard reset. Sometimes it'll be while playing a game, sometimes while watching video, sometimes just browsing the net. Sometimes it'll nto happen for a week, sometimes it'll happen multiple times in one day.
Motherboard: GigaByte GA-X58A-UD3R Intel X58
Power Supply: Be Quiet 900watt Dark Power Pro BN125, P8 Silver 91% Eff. 4x PCIe, 4x 12V
Display Devices / Connections: Dell UltraSharp U2711, through DVI
Applications and games: Various, as above. Not linked to specific applications.
CPU details: Intel(R) Core(TM) i7-950 3.06 GHz 8M Intel Smart Cache LGA1366, no overclocking
Motherboard BIOS: No idea, but it's the same as it was before I changed to this graphics card, back when this issue didn't occur, so I'm going to go ahead and guess it's not this.
System memory: 6GB (3x2GB) PC12800 DDR3/1600mhz
Additional Hardware: Primary HDD: 64 GB Crucial C300 Series SATA III Gaming MLC Solid State Disk
Secondary HDD: 1TB SATA-III 6.0Gb/s 64MBCache 7200RPM Hard Drive
Case fans: 4
Optical drives: 24 speed DVD rewriter
Additional details: Virus scan (AVG) and spyware scan (spybot) clean.
Hopefully that's enough info. Anyone able to provide any help?