Windows Vista Low power on startup and KSOD Vista X64

Can any one help with my start up problem?

For my desktop pc I have a power and boot up problem that does like this...

Turn on main front power button
BIOS screens run through all OK
Windows startup screen runs OK (with the flashing green/yellow bar)
Then what normally happens is a pause of one or two seconds before the Windows icon appears and I can login.

What has been occurring recently is at this pause, the screen stays black and the computer goes into what can only be described as a low power mode. I sense this as the fan speed reduces, sometimes uneven and the screen stays black. Nothing else will happen.

BUT if I turn the pc off at the main power button at the rear and switch on again it will boot up, all through the processes with no problems. However if I do this at the stage above I have effectively forced a shut down and Windows enter via the recovery, but this still works fine. Windows etc works then with no problems at all.

Also if after shutting the PC down correctly I turn off the rear power button and turn it on before start up, all starts OK.

No devices are connected and powered on at start up other than Netgear router. I have disabled the devices (Control panel, Device manager, Properties) to “wake” the computer (mouse and keyboard) and also the Network Adapter, all of which were causing problems in waking the computer. This was a while ago and has been working fine for many months.

Any good ideas would be appreciated. Could it be a software problem (drivers?) or a hardware problem (power supply?)

Have run diagnostics on memory, fans and drives and all OK. If I restart then all logs in to Windows icon OK.

 

The drivers (software) that load just before logon are the graphics.

I would find the latest drivers from the graphics adapter manufacturer's website, go to Control Panel -> Programs and Features and you should find a listing for the graphics drivers. I would uninstall those, then reboot and install the new drivers. If you come across any problems, boot to the Startup Options menu (F8) and select Low Resolution mode.

Maybe, because you have had to make BIOS settings, the CMOS battery might be running low, so try changing it (I assume it is a desktop computer, not a laptop).

Power Supply...possibly. I find another (similarly rated) PSU that I can borrow and use that for testing.

You will need to supply the system details if you would like specific help.

Matt

 

Hi - thanks for the response.
I have checked and updated the graphics driver and though this had done the job - but not OK on a restart bbut not on a normal boot up.

The odd thing is, when the computer boots up from start, it will get to the Windows screen with the flashing bar and just before the main icon, it will stop and then a sec or so later, restart itself. But I have noticed also, when it does this, apart from going on a low power mode, the screen stays on standby mode. And so the only way forward is to turn off the power via the power switch on the rear. If I do this it will boot up all OK, although it will enter the 3 option mode, but when proceeding direct to Windows is still then OK. Also if I turn off the power switch after I have shut down correctly, turn it back on again before starting up again, all is OK

It is almost as if, at the final point of completing the startup procedure, some process or otherwise is preventing it completing to logon stage, but this is removed if the power is "turn off and back on again ". The pc and Windows itself all work fine once this power up has been overcome.

Is there any way to check the remaining power in the CMOS battery without taking the pc apart?

The other thing you suggested was the power supply and it does sort of point to this. BUT the thing is, once I have reset the power on the rear it all works OK - every time! If it was the power supply, wouldn't the pc be unstable?

Any other suggestions would be much appreciated.

 

The CMOS battery is no big deal to get to. Take the side cover off the Desktop and you will see it. It is about the size of a nickel and are about 3 bucks to replace one. They are like any other battery. Look good with a meter and then load them and they will be weak. I have a couple of PC's that are about 13 or 14 years old and still have the same battery that came from the factory. One of them hadn't been turned on for about 5 or 6 years and booted right up. It wasn't plugged into electricity that whole time either.

 

Try going to the Startup Options menu (F8) from a "cold boot" (when it normally has the problem). Try Safe mode and Low resolution mode. That would point to (graphics) drivers, because they are not loaded in those modes.

What sort of graphics adapter does it have, onboard or an add-in card?

At the point it restarts, is there any sign of a blue screen? Try using the information from here to see if dump files are being generated:
http://www.windowsbbs.com/general-d...-collection-tool-instructions.html#post175971

If there does not seem to be .dmp files, it may be due to bad voltage or (components) overheating.

I won't theorise any further at the moment. You need to start testing the software, like drivers and whatever hardware you can "swap out ".

I haven't seen the problem you describe before. Some systems I work on have very strange problems, but then, you need to think "outside the square" and start testing whatever software/hardware might seem to be involved.

Matt

 

Something else I thought of trying is to run Error Checking (CHKDSK). I take it you know about it, otherwise look up Error Checking in Help and Support. Also, set it to run a scan of the disk surface (for bad sectors). Be prepared that it might take many hours to run, so say, leave it to run overnight.