BIOS: Disabled CPU -> How to change back

Ok, first off, this is not my problem, but my sister’s (so in a way it is my problem too, but I am not the one who caused it :wink: )

Yesterday, my sister started her PC and some error message appeared, made her go into BIOS. Don’t think she changed much the first time, but after booting into Windows, her printer needed reinstalling. So she did.

After reboot for completion of printer installation, another error appeared (forgot what the exact errors were, but it had something to do with CPU (or VPU as she first described it)). She went into the BIOS and recognised CPU from the error message. She saw enabled next to it and decided to disable it (I am not sure if it is possible, but she may have disabled her CPU).

Now that she changed the setting, her PC won’t even boot, her screen stays black. Turning power off and back on when holding ‘Del’ will not get her into the BIOS.

I was not able to help her over the phone, don’t even remember the make and model of her PC. But before I rush over and take the machine apart, I was hoping that someone here would have an idea how to fix this (could it be a virus?)

Many thanks in advance (also on behalf of my sister)!

Sounds like you will have to clear the CMOS…that should fix the problem if it is just a badly configured bios.

Yes it does :slight_smile:

Most mainboards have a jumper to clear the BIOS. Often these jumpers are labeled as “CLEAR_CMOS”. Turn off the system, toggle or move the jumper, wait a few seconds, put it back and turn the system on. If everything went well, you should have a picture.

Can sometimes be difficult to locate the right jumper, so keep the motherboard manual handy if you still have it.

Brand names, Tax. We need brand names.

Give him a break…he’s “non-technical” remember :wink: :stuck_out_tongue:

You can also take out the battery of the mobo for a couple of minutes. Cleared the cmos on my system after I pushed an overlcock too far and couldn’t startup.

you need to tell him that under no circumstance should he do this with power plugged in or god forbid on.

Doesn’t matter , If i know the brand name and type i’ll be able to pinpoint the location of the cmos reset far easier. Nowadays the reset usually is just two solder points.

Just pull out the battery (unplug the power cable to the PSU of course) as somesone said for like half an hour. It’s an easier/faster way than identifying the mainboard and ask for help on a forum where the jumper is located. :wink:
//Danne

Why jump the gun to clear the BIOS, why not try load BIOS defaults first?

Yes a brand nam eof the System in question would be very helpful. :wink:

Because he doesn’t get that far?
“Now that she changed the setting, her PC won’t even boot, her screen stays black. Turning power off and back on when holding ‘Del’ will not get her into the BIOS.”
//Danne

An old method of defaulting the BIOS, on some machines, was to hold the INS key at power on - it may not have carried through to current times, but worth a try.

Sometimes tapping the the reset switch twice may trigger a BIOS reset, but these are OLD methods.

The only sure way is to find the “clear cmos” jumper, or if no jumper, then removing the battery for a couple of minutes should do - and yes, you don’t want power at all, not even the standby state of a supposedly “OFF” ATX power supply.

old proggie called killCMOS or something I used to use on a bootable floppy disk with an autoexec.bat :wink:

Maybe it was an option about CPU cache or hyperthreading tax?

Thanks for all your answers so far.

I have no idea what exactly it is she changed…don’t even know what her current PC is… But she will pick up the PC and bring it over and I’ll see…

I think I will go for the clear CMOS option, hopefully she still has the booklet of the mobo, but even without I think I can manage (thanks to the internet)…

Let you know what turns out.

At least, these days, you don’t have to know the drive type or geometry of the hard disk after a CMOS clear - the majority of systems have quite adequate autoset.

You MAY need to know what the processor is, as that may need a setting, or it may be fully auto.

Go with SETUP defaults (or “optimal”) - BIOS and reset defaults tend to be not just “safe” settings, but crippled with caches off and everything set as slack as possible.

My sister brought her PC yesterday. Turned out to be MSI 6163 mainboard.
Found the clear CMOS jumper and the problem appears to be solved.

Thanks for your input!!

my brand new DFI lanparty pro875b rev b. is getting same blank screen never make it to cmos, no beeps all D-LEDs show ready to boot. do u think mobo is DoA, or could the jumper fix problem for me too , other specs kingston hyper-x ddr400 dual channel 1g ( 512x2 ) set in slot 1 and 2. geforce 5700le 128ddr , maxtor ata133 HD, have both dvd and HD plug set primary to system ( no slave set ),any help would be great got my life savings in this puter… thanks