Help/Advice: PC Power Up/Down Loop BIOS and Windows.

[GlobusDiablo]

...My suggestion remain the same as always, grab your windows disk/usb drive. Boot from it.
If you want you can leave it running on the first setup screen for a while to see if it randomly reboots again but I would find that very unlikely.

I approved this message.

Fingers crossed Avi.

[Avago-Earo]

OK, here's an update.

Today I switched on the PC and after several ON/Off cycles and failing to get into EUFI BIOS a Windows screen appeared with a message like (I didn't have a pen handy) 'Diagnosing Systen' or similar. I was then presented with a screen saying something like 'didn't boot properly' or similar with the following options: 'Restart' or 'Advanced'. I chose restart hoping Windows would do some sort of reconfiguration or what have you, but it went to the 'Windows Starting' Screen, the one after your email account screen (8.1) and after a while went to 'Shutting Down'. Then the PC switched on and off in quick succession about four or five times until shutting down completely.

It still doesn't explain why at first it switched on and off at the beginning without going to BIOS, just the ASUS logo. Could Windows do that even though I don't see how the Hard Drive could be addressed at this stage?

If I remove the Hard drive would that confirm it's not a Windows thing? I assume so as that's where Win lives. I may change the Thermal Paste as it's probably overdue and I've read that an over heating CPU can cause start up failures.

[TorTorden]

You don't need to change the thermal paste EVER unless you replace cpu or reseat it in a new mobo.
When something isn't broken, there is no need to fix it, unless your computer is overheating constantly for example the CPU reaches 80+c on regular basis and not cooling down, stable temps in 50-65c range is not a problem.

I have been buidling and maintaining computers since the mid 90's and I have never needed to replace the paste without mechanically damaging its application, even after a decade of operation.

At this point I would turn on the comp, and go watch a movie or something, either it will finally decide to present an actuall error message or it will sort itself out and probably load a restore point pre the win 10 attempt.
This can take awhile as in anywhere between five minutes or 20 hours.
Just let it run.

[Avago-Earo]

Cheers TorTorden.

I've already switched it on as I described above and it did it's thing and switched off. It didn't go to Windows, just the loading screen. And why when it shut down would it switch on and off about once a second about four or five times?

I've seen in a lot of tech sites/forums that thermal paste should be changed yearly. I'm new to this so google/YouTube are my only options. You've shed light on matters. Cheers.

[Avago-Earo]

Won't even go to the Asus logo now. Switches On and off 3-4 times and switches off.

[Avago-Earo]

Now it's randomly switching itself off and on

[GlobusDiablo]

Now it's randomly switching itself off and on

Are you able to reinstall windows at all? Do you have external media to boot from? Windows on a cd or usb/external hard drive?

[Avago-Earo]

Now it's randomly switching itself off and on

Are you able to reinstall windows at all? Do you have external media to boot from? Windows on a cd or usb/external hard drive?

I have Win 8.1 on DVD but I can't get into the EUFI to enabe boot options because it switches off before then.

It was going on/off as fast as flicking a light light switch. Then a few seconds pass and it happens again. Then it just went on and off for five minutes. The Asus screen appeared for a split second. Then it kept going on and off. Sometimes I'd hear the POST Tone and immediately Off. Repeated that for another five minutes so I flipped the power switch on the back.

The PSU came with the case. No brand so it could be that.

[GlobusDiablo]

I have Win 8.1 on DVD but I can't get into the EUFI to enabe boot options because it switches off before then...

Damn.

[Zadkiel]

Now it's randomly switching itself off and on

I already told you what the problem is, back on the previous page.