Laptop restarts unexpetedly without warning

Problem: My HP Pavilion dv5000 series laptop keeps restarting on it's own. It happens at no set interval of time and doesn't always happen during the same activity. Sometimes I'll have just started it, go online, and then it restarts. Other times it's good for a longer period of time before restarting. It happens most often when I am online (I use firefox typically). It also will restart during a virus scan. I recently had it started in safe mode and ran a virus scan with avg free, and a few minutes into the scan it restarted again. I haven't had any viruses(as far as I know) or major problems prior to this. Sometimes when it restarts it lets me stay on for a few minutes before doing it again, sometimes it restarts 3-4 times in a row before it lets me stay on long enough to turn it off or start in safe mode. My laptop is just over 2 years old of pretty constant use (it is my main computer).

Thoughts: Could my system be overheating? (i would think it would shut down though, vs. restarting.. but have no idea in reality)

What I've done/found:
1. I followed advice to turn off the automatic restart function. It still restarts without a warning though.

2. I've looked at the event logs, and occassionally there are some errors in the system around the time of it restarting, but it's never consistent, and often there are no warnings/errors around the restart time.

3. I installed speedfan, and the past two times my computer restarted, I think the Core temp. was at 51 C, and it had the flame symbol by it, so I think it may be overheating? 51 C sounds low to me though compared to some people's I've read online. I don't know what my system should be at though.

There's my information thusfar for you.
Any thoughts on if it is actually over heating or any other problems?

If you need more information, just tell me what you want and where to find it, and I'll get it up ASAP. I try my hardest to know it all, but I'm pretty illiterate when it comes to all this!
Thanks for any and all help in advance!

 

Ok, so I think I downloaded the file but when I got to running it, it didn't list the tools. Before I could figure anything else out/ look around for it, etc. My computer shut down. Note, this is the first time that my computer shut down, and the first time it gave me the Blue Screen Of Death like it should (since I disbled automatic restart a while back).

On the screen, it gave me this stop error:
0x0000007f (0x00000008,0xf78aad70,0x00000000,0x00000000)
It also noted that it was writing a dump entry and that it completed doing such, so I know the dump is indeed activated. It's just a matter of getting to it.

I restarted, and looked at the temperatures just to note them. The ones that had the flame symbol by them were the temp. 1 was 55C and the core temps were around 51-53C (using speedfan)

I tried to get back to working on finding the dump log, but it restarted within a minute or so of booting up. I'm going to have to wait a while before trying again either later tonight or tomorrow.

 

Ok, so I downloaded SIW no problems. But, now what? Which information should I post for help? There's a lot of categories and a lot of information, so I want to make sure I list all the useful information

 

CPU INFO
Property Value
Number of CPU(s) One Physical Processor / 2 Cores / 2 Logical Processors / 32 bits
CPU Full Name Genuine Intel(R) CPU T2300 @ 1.66GHz
Vendor GenuineIntel
CPU Name Intel Core Duo T2300
CPU Code Name Yonah
Platform Name Socket 479 mPGA
Revision C0
Technology 65 nm
Instructions MMX, SSE, SSE2, SSE3, XD, VMX, EST
Original Clock 1666 MHz
Original System Clock 166 MHz
Original Multiplier 10.1
CPU Clock 1669 MHz
System Clock 166.3 MHz
FSB 665.0 MHz
L1 Data Cache 2 x 32 KBytes
L1 Instructions Cache 2 x 32 KBytes
L2 Cache 2048 Kbytes

Sensors Value Min Max
ACPI
Temperatures
TZ01 46C (114F) 42C (107F) 55C (130F)
TZ02 0C (32F) 0C (32F) 0C (32F)
Intel Core Duo T2300
Temperatures
Core #0 51C (123F) 42C (107F) 54C (129F)
Core #1 51C (123F) 42C (107F) 55C (130F)
FUJITSU MHV2100BH
Temperatures
HDD 33C (91F) 25C (76F) 34C (93F)

I think that's all the information on the temperature and cpu specs, but I couldn't find fan speeds or voltages anywhere. I tried to look online to see if I could figure out where that information would be, and I think it should be in the sensors section, but there was only temperatures in that section for me. If you think it may be somewhere else, let me know. About 5 min. after collecting this data, I kept looking around for the information and turned on speedfan, to see if I could find the missing info on there (with no luck), and then my computer started its habit of restarting again.