System keeps restarting, no blue screen

My Windows 7 laptop will power on and start up without a problem but it will suddenly restart without any notice. I turned off the automatic restart on system failure and it still restarts. It also restarts in safe mode with networking but not in the "regular" safe mode.

I did, somehow, get a blue screen once with this error message:
STOP: 0x0000001E (0xFFFFFFFFC0000005, 0xFFFFF8000377B7DA, 0x0000000000000001, 0x0000000000000018)
Never saw a blue screen since this.

Startup Repair- could not repair automatically
system restore- I restored it to three previous points but still having same issue

Running Windows 7 Home SP1 64-bit
Toshiba Satellite C655
Processor: pentium dual-core CPU T4500 @ 2.30GHZ
RAM 4.00 GB (3.87 GB usable)