Random Rebooting?

[DeleriumMDK]

Alright I've had my PC for...um 2 years in June I think. The one problem I had was hard drive related, changed it, re-installed Windows and everything is running smoothly, or was for a year or so. Now, very rarely, I double click a program to run it, black screen, and my system reboots. I know its not a heating issue as my PC is kept reasonably cool, its got decent enough fans inside of it.

Hardware wise Ive got 2 5.25 "drives, CD-RW(NEC NR7900), DVD-/+RW (NEC ND1300A). For USB devices I have X-Port (Gamesave transporting with PS2...only draws power when in use as far as I know), and a Logitech Wingman Rumblepad which constantly draws power I believe (lights always on). For hard drives I have a 40GB Maxtor, and a 120GB Seagate. Running Pentium 4, 1.7GHZ, 256MB DDR SDRAM, NVidia GEForce 2MX 64MB, my Mobo is Intel 845D I believe.

Oddly enough...this black screen -> reboot is the only issue going on now. Everything else seems to be fine, I've done a check for viruses, nothing. Not Trojans, my system is cleaned of spyware EVERY day with Spybot Search and Destroy. I'm on a shared internet connection and the only ports I've opened are for my XBox Live service and only apply to that IP Address so I don't think it would affect my computer. Anyone have any ideas on what could cause this? I'm not all that worried but just curious as it seems to happen at the most inconvenient times, during important conversations with friends. The two times it occured it was with different programs, first I went to run DVDDecrypter, second time was when I tried to run CDEX.

[mujahid7ia]

The two times it occured it was with different programs, first I went to run DVDDecrypter, second time was when I tried to run CDEX.

Both optical drive related problems - can that be related? Also, do you have a spare PSU you can swap in?

Also remove all components, replace one-by-one and test until problem occurs. The last thing you (re-) installed has the problem...

[DeleriumMDK]

I've got 2 spare PSU's, none anywhere NEAR powerful enough. I think half as powerful as this one in my machine now. Odd part is though with these applications...I didn't have a disk in either drive when I accessed the programs. Its very flukish, this random rebooting. I don't know if I want to go and completely remove everything and slowly re-add it back as its only occured twice. If it becomes frequent, then yeah without a question I will do that, but for now I was just kind of curious as to what could be the cause, and if anyone else has experienced this.

[Piccoro]

What is your PSU's Watt rating?
Do you think something could be wrong with the PSU, line noise or maybe one of the rails is starting to wear out?

[DeleriumMDK]

250 Watt...heat Dissipation 534 BTU it says.

[DeleriumMDK]

And what exactly do you mean by rails and line noise? I'm a bit of a novice when it comes to hardware. Most advanced stuff I've done is adding RAM, a hard drive, or 5.25" optical drive...

[Piccoro]

Link

Powersupplies have 3 rails which is how it splits off into different voltages after it converts AC to DC.
e.i. If you add too many devices using the Molex connections (HDD,Optical drives), that is using the 12v rail, and the amount of power in use exceeds what it can dish out then your PC restarts.

If you live in a home that has poor/old wiring or out in the country...a lot of times there is noise on the line and when your PSU converts AC to DC it may get too much above or below +12volts for the 12v rail and cause your PC to restart again.