Random restarts on computer

I have had a problem with my computer restarting at random for awhile now, I have
1)ran memtest86 overnight and while at work for 14 passes with no errors.
2)Checked the temperatures for overheating with speedfan, system and cpu under 34c
3) Formated hard drive and re-installed windows

my suspicion is that it may be the power supply, what do I look for when looking at wattage in the bios? And here is my system information from cpu-z (not all, its very long, please ask if more info is needed.)

Processors Information
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Processor 1 ID = 0
Number of cores 4 (max 4)
Number of threads 4 (max 4)
Name AMD FX-4100
Codename Zambezi
Specification AMD FX(tm)-4100 Quad-Core Processor
Package Socket AM3+ (942)
CPUID F.1.2
Extended CPUID 15.1
Core Stepping OR-B2
Technology 32 nm
TDP Limit 95 Watts
Core Speed 3300.1 MHz
Multiplier x FSB 16.5 x 200.0 MHz
Rated Bus speed 2200.1 MHz
Stock frequency 3600 MHz

Display Adapters
-------------------------------------------------------------------------

Display adapter 0
Name NVIDIA GeForce GT 430
Revision A1
Memory size 2047 MB
PCI device bus 1 (0x1), device 0 (0x0), function 0 (0x0)
Vendor ID 0x10DE (0x196E)
Model ID 0x0DE1 (0x0829)

Motherboard
MSI
Model Number MS7641

Power Supply Thermaltake TR2-600w
Model Number TR2-600nl2nh


Any help would be greatly appreciated, especially on where to look to see if power supply is indeed failing/bad.