Pc won't boot out of safe mode AND intermittently restarts.

[holy god of nil]

My old PC which I don't use much has developed some strange issues which I'm at a bit of a loss about. First background;
I'm running these specs with windows 7:
i5 2500
Asus p8h67
16gb DDR3
1TB Samsung + 120GB Sandisk Extreme
Sapphire 7850 OC
Corsair HX450
Silverstone SG03

And until last week it seemed rock solid. I had windows 10 scheduled to install but the computer was off at the time. Anyway a couple of days ago I booted the PC and went downstairs, when I came back up it was frozen on a the desktop with the Windows 10 program showing 50 mins to install (or download, I'm not certain) and a driver update showing it was ready (I think either from my AMD for the graphics card or avast).

I powered down using the case button and ever since have had the following issues: Windows won't boot normally or in repair mode but will boot in safe mode and safe mode with networking (I have done a system restore to a time before the windows 10 was scheduled). As well as this the computer intermittently cuts out like it has lost power and then immediately starts back up.

I have done the following things: reseated the ram, checked temps which all seem fine, removed the graphics card, checked the bios settings (date and time etc are all fine) and generally had a check of cables etc.

My assumption would be something is shorting / the psu is dying BUT why would it not boot except in safe mode then? I'm confused and any ideas are welcome.

[holy god of nil]

It also seems to be the booting which causes the PC to cut out, as it is solid on bios / windows memory checker etc pre-boot.

Note that it doesn't always cut out, though it seems to be doing it more and more quickly now.

[DanceswithUnix]

Sounds like PSU or motherboard to me.
Running memtest86 is usually an easy and useful test on things like this as well, as faulty ram could fit.

Do you have parts you can swap out?

My recent motherboard failure was similarly strange. Once booted the PC would stay up for ages, but it didn't want to reboot and would take increasing numbers of goes. Booting into Linux was more successful than Windows, perhaps because Windows is on SSD so the machine gets fed with stuff faster. Finally it wouldn't recognise anything on the SATA ports but would boot OK from USB stick. I can only guess that the south bridge was peeling off the PCB or something.

PCs are complex, and not always obvious.

[holy god of nil]

Yeah that more or less mirrors my thoughts, it now seems to be failing so quickly and regularly that running memtest won't be an option.

Unfortunately I don't have spares, a recent house move put pay to the majority of my old bits and as it's an mATX 1155 mobo I need it may prove challenging to pick up one easily.

BTW any know if a PSU tester would provide any useful data about whether my unit is failing, I'm presuming not?

[DanceswithUnix]

1155 is still OK to get hold of, albeit with limited choice. I bought my mum something like http://www.ebuyer.com/429725-asrock-...board-h61m-dgs for a Xeon that got thrown out at work to go in. That only has 2 DIMM slots, but pretty good for the price if you don't want to overclock.

I bought a PSU tester some time back. Haven't had a PSU fail since, so you could call that a success Given how cheap they are it could be worth a punt on one.

[c12038]

Sounds like windows is corrupted and its put its self in a boot shutdown loop

[holy god of nil]

I thought that but now I can't even boot into ultimate boot cd (and even when I can I can't use my keyboard despite legacy support being on). I'm chalking this one down to the mobo currently as dances says.

[holy god of nil]

I never did get round to fixing this, it's a very frustrating problem. Just took delivery of a new PSU and mobo for testing purposes, think I should get some new DDR3 too mind, though it seems more expensive now than it was when I last upgraded!

[holy god of nil]

Also I can't boot from my (legit) windows CD - It just sits on the loading windows screen, I can't fathom that one.

[kalniel]

Also I can't boot from my (legit) windows CD - It just sits on the loading windows screen, I can't fathom that one.

That could be a drivers thing, particularly storage eg sata2 or AHCI.

[holy god of nil]

One day hopefully I'll be able to boot into something for long enough to think about fixing that!

[excalibur2]

If you can get in safe mode can you use "chkdsk" or "sfc /scannow" to check the hard drive for corruption that could prevent the OS to properly load?

[davb]

Have you tried booting from a CD with the hard drives disconnected, in case one of those is faulty.

[holy god of nil]

Thought I'd fixed it with new MB, checked the HDDs and they seemed fine - fresh install of windows, all looking rosy then bang blue screen of death and it's back to its old tricks. I am officially stumped, I guess this leaves RAM all over again (anyone got a stick or two of DDR3 I could borrow to test with?) or CPU?!!

EDIT:

Apparently my CPU is running at 99c, tempted to chalk that one down to a borked sensor as the air coming out feels nice and cool but hmm...

[kalniel]

Apparently my CPU is running at 99c, tempted to chalk that one down to a borked sensor as the air coming out feels nice and cool but hmm...

If the air's cool then you've got a problem... you want the air to be carrying the heat out.

[holy god of nil]

Aye - I will resit the heatsink tomorrow just in case.