Help my PC randomly reboots

[swordzero001]

Help my PC randomly reboots I've already disable the option to restart on error and it just keeps rebooting, I had this problem for a while and last week it stopped out of nowhere and it's back now.
Additional Info: Sometimes it doesn't even reboot it turns off and the red light stays on for a while until it finally turns on, also at least on 2 ocassions it reboted during BIOS setup. My Photoshop says there's a problem with GPU (Upgrades/Tweaks/Bonus)(sorry I use Photoshop in Spanish) I don't think it's temperature it reboots it sometimes reboots on Windows booting screen (When first turn on)
Processor: AMD Athlon(tm) 64 X2 Dual Core Processor 4000+
Motherboard: ASUS M2N-MX SE Plus
Graphics Card: NVIDIA GeForce 6150SE nForce 430 (512 MB)
Another thing i bought a RAM Kingston but it's slim (KVR667D2N5/1G) it has the same specs as my current RAM except this is Slim, Can I use both?

 

[Anti-Trend]

Hmm, the RAM timings being different may cause problems for you. For timings, you'll have to make sure you're using the lowest common denominator of the two sticks. If this is being automatically set by the BIOS, it is sometimes helpful to have the one with the loosest timing in the 1st slot of the 1st bank.

As for the rebooting issue, it could indeed be a memory problem, could be a bad on insufficient PSU, or it could be one of many other problems.

1. What is the make & model of your PSU?
2. Have you tried running Memtest86+ overnight?
3. Have you sniffed around the mobo for bad caps?

 

[swordzero001]

@Anti-Trend
1 My PSU is generic, nothing wrong at plain sight a technician friend of mine looked at it though he didn't replace it or actually test voltage but if I use less elcetricity (i.e. DVD Drive) it still rebbots Is there a way to find out by myself without a shock.
2 Yeah plus it rebooted when I was using another RAM stick (not the new one)
3 Yes, found nothing
About RAM as I said they are identical except for the size, according to Kingston website it's compatible with my PC but if the 2 together could cause trouble could you tell me what I'm supposed to configure in the BIOS.

 

[Anti-Trend]

1 My PSU is generic, nothing wrong at plain sight a technician friend of mine looked at it though he didn't replace it or actually test voltage but if I use less elcetricity (i.e. DVD Drive) it still rebbots Is there a way to find out by myself without a shock.

To be honest with you, generic PSUs are more or less worthless; you can't trust them to reliably output even 1/3 of the power they're rated for in some cases.

Also, unless they catch fire, PSUs don't usually give a clear indication of their failure except symptoms like the ones you're having. There are ways of testing it, but they require some good electrical skills and some extra equipment (which if you had, I'm sure you would have used already). It might be fine, but what you need to ask yourself is if it's worth it to hold onto the most cheap but important component in your computer, or replace it with something reliable.

2 Yeah plus it rebooted when I was using another RAM stick (not the new one)

I would make sure that the RAM is running at the rated timings and voltage, then run a thorough test overnight with the latest build of Memtest86+ (it'll be 4.0 as of this writing).

3 Yes, found nothing
About RAM as I said they are identical except for the size, according to Kingston website it's compatible with my PC but if the 2 together could cause trouble could you tell me what I'm supposed to configure in the BIOS.

ASUS motherboards have a lot to tweak, and to be honest I don't really have time to research all the possible settings of your motherboard for you. But, in general, non-matching sets in a modern system are a really bad idea. You will have problems with uneven voltage requirements, unequal timings, and uneven memory sizes in dual-channel mode.

Assuming its possible to get them playing nice together, you've got to go with the lowest common denominator between them. In other words, you will need to set all RAM to at least the minimum voltage of the RAM stick with the highest requirements, use the highest latencies of the two, and maybe disable dual-channel operation altogether. If the voltage requirements are uneven, e.g. one stick needs 2.2v and the other 1.8v, you're likely to fry the lower-voltage DIMM. In that situation, your memory is simply incompatible with eachother.

 

[swordzero001]

Thanks
I did ran memtest86+ 4.00 and gave me no errors
Both RAM sticks have same voltage, pins, same everything except size (actual physical size)
Gonna try to see if I can get someone to check my PSU agin thanks.