PC crashes

Hi,
Sorry if this not the right place to post.
I have a Pentium 4 with XP Pro SP2, Mob Azus, video card Radion 7000, 1 GB ram
This morning I found that my PC had shut down without warning while in the middle of converting a video file.
Every time I turn it on, it will launch Windows with no problem but then crash again after a few minutes even without opening another program.
I have not installed anything recently.
It does not stay on long enough for me to run the anti-virus.
I cannot open it in safe mode. It jumps to the boot disk, which I do not have :-o.
Any idea what could have triggered that behaviour since the PC was not doing anything out of the ordinary?
Should I provide some more information?
Thanks in anticipation

 

When you say the PC crashes, do you mean that it errors and you get an error message? Or is it locking up? Or is it just shutting off? If you have an error message or error number (like 0x000000ED for example), please post it. If the PC is shutting off, this is usually because something is overheating. Converting videos is a stressful task for the CPU and if it is not being cooled correctly, the PC will shut down to try to prevent thermal damage. I'm not really sure what this means:

I've been working on PCs for a long time, and I have never seen or heard of safe mode "jumping to a boot disk". Maybe you can explain this a bit more clearly....
:-D

 

Thanks for your reply.
Sorry if I did not use the proper words. I meant that it shuts itself off.
If it were overheating, wouldn't it go back to normal after several hours? Since this is not the first time I am doing it, could it be a sign that my PC is getting old?

I press F8 before it launches Windows and normally it goes to the screen where you can choose Safe Mode. But instead I only see a glimse of that screen and it jumps to a blue screen where I am asked to choose where my boot disk is.

 

Boot device

 

Is it possible that an account may be corrupted and would make the PC shut down.
I normally use a user account but today I used my admin account and it seems to have less problems.

 

check your system files for corruption, type sfc /scannow in the command prompt
this will help you...

 

Thanks jblim, I will try that.
However, it seems that whatever account I use, when I open a program that is resource consuming or several programs, it shuts off after a few minutes.
Would that be confirming dlb's suggestion of overheating?
and if so, am I correct to assume that it is more a hardware than a software issue?

 

The Windows File Protection verification just closed after finishing scanning. Does it mean that there is no problem in that regard?

Correction: without opening anything else, the PC shut off after a while.

 

it may be dusty in the the cabinet, and accumulation on the fans & motherboard ,get a can of compressed air to blow the dust off the heat sinks,fans,circuit boards,
my pc shuts down the same way when the insides get too dusty and overheats.

 

I did a serious dusting and so far so good.
24 hours non stop! and still running. I didn't use any heavy program yet and I keep my fingers crossed
Thanks mimon for the tip.

What about my inability to access the safe mode?