Unknown Problem causing crash

Firstly I don't know if this is the correct sub-forum so if I'm wrong apologoes in advance.

I'm running a desktop PC on windows xp home xp3 and I access the internet on a dongle in UK from 3G. This is usually connected to a USB point at the rear of the computer.

I don't know if this is relevant, I think it has a peripheral bearing, but I have an external drive connected by USB. I've had this for several years and when I connected it a few days ago it didnt show up on the control panel. I put this down to age (mine and the ED) and didnt think too much about it.

Three days ago, whilst watching the internet, the PC just shut down. It's programmed to auto start and did so but kept shutting down again at various stages of boot up.

Eventually it started up properly but when I tried to insert ANY USB into the computer it shut down again; this includes memory stick. I should point out that the other USB functions eg mouse, keyboard and headset are fine.

Anyway the current position is this: From time to time whilst using the internet the PC shuts down. If I start up with the dongle attached 99% of the time it just gets to the 'Welcome' screen and re-starts. If I re-start without the dongle attached 100% it starts fine but when I try to insert the dongle it shuts down again. The same thing happens if I attach the external drive but for some reaon NOT the memory stick. So it seems odd that now the memory stick doesn't cause a problem whilst the dongle and the external drive do.

Obviously there is a problem which I imagine will be beyond my meagre brain to repair, but can anyone suggest a likely cause which hopefully will not cost me an arm and a leg to repair.

If anyone replies can I request that you keeps your replies simple as I am not very advanced in anything other that age!.

Thanks
Cozzie

PS Hopefully the PC will be in a benevolent mood when you reply.

 

Do you get the same resulting issue whilst in "safemode" (f8 @reboot), this may not be a hardware issue it could be viral/malware, and if all is well in safemode will confirm this.

 

Is the same with safe mode, usually I just get to where the files are scrolling down and then it shuts down. I've run Malwarebytes and microsoft security essentials with the latest definitions but they are showing nothing.

I Just looked at the Event viewer and see one recurrent error is MatSvc, could this be relevant?

 

Re my last, the full error message reads
The scheduled MATS task encountered a failure when collecting configuration data
hr-0xC004F00E

 

I doubt very much that that is the cause as it is part of the MSfix it tool.

I am thinking that it is either a driver issue or over heating, when was the last time you gave your machine a good clean out ?? try cleaning the gold contacts on your ram and gpu(if one is installed) pay peticular attention to the cpu fan, make sure that it is not gungked up with dust, give it a good blow out, use a plastic stick to stop the fan from spinning when blowing it out as it may damage the barings, same goes for psu/gpu and any case fans.
Re install your chipset driver also.

 

Possibly marginal power supply. Your current power supply no longer has enough power to run the innards and supply power to ALL the devices plugged into the USB ports. (mice and keyboard don't use much power)
Try a stronger power supply.

 

Plodr, thanks for your last reply in september (just got the computer back from the shop). You were absolutely right about the power.
I hope this might help anyone else with a similar problem.
Cozzie