Non system disk error

in Techie Stuff
15 replies 1.3K views
My laptop which is about 4 years old has just thrown in the towel ( I think!)
On switching it on, it comes up with 'Non system disk error'. Nothing i do seems to fix it. It doesn't read the floppy so i can reinstall windows 98SE . When i play with the bios info ( i.e press delete on switching it on)and try booting from CD that makes no difference.
Someone at work suggested my hard disk may be corrupted and it is time to put the computer to sleep permanently.
Can anyone help resuscitate one last time?


  • frakfrak Forumite
    112 Posts
    The master boot record has failed. Usually it has become corrupted. you need to be aable to boot to a command line. You would normally do this by a floppy boot disk. However it can also be done using a bootable CD that has a DOS based OS or a bootable version of Windows 98. The command you need to execute is fdisk /mbr

    However i think you may struggle to do this as explaining how to create bootable cd's is a little beyond the scope of what i can explain here. The only other option is to find a friend with a laptop that has a floppy drive that works. Put your hard disk in it. Boot off a windows 98 start up disk and execute the command above.

    Dig inside; inside is the fountain of good, and it will forever flow, if you will forever dig.
  • debeastdebeast Forumite
    190 Posts
    Frak is correct

    You will need a Bootable copy of Win98 or windows millenium in order to repair the boot record!

    ask at work or your mates :)
    -34k to 0 from september '05
    Debt Free, Stoozing King, Shrewd spender
  • zainzain Forumite
    336 Posts

    However i am not sure how i can replace the hard disk from one laptop to another? Is that what you mean?
  • MisterT2MisterT2 Forumite
    166 Posts
    You said that it wouldn't read from floppy. I know you have been given some good advice above, but it is starting to sound like there might be an issue with the CMOS settings.

    Before doing anything, lets see if we can get the floppy working. Go into the BIOS as the system is starting. Depending on the BIOS, find something that says boot sequence or boot order and make the floppy disk the first entry (it sounds like the hard disk is the currently the first entry).

    If you make this change, then the drive light on the floppy should illuminate next time you boot.

    If this doesn't work, then the next thing to do would be to check that the CMOS settings are correct for the hard drive. . One very clear indicator that the CMOS has failed or become corrupted is that the system date is wrong and memory settings are default.

    There is usually some hard disk autodetect routine in the BIOS (usually as a subprogram of the hard disk routines). If this replaces the hard disk values with something different, then it is very likely that the CMOS battery failed (and that the laptop had not been plugged in for some time). If this is true, leaving the laptop plugged in for a while might "fix" the problem. If that doesn't work, then you might need to replace the CMOS battery which is normally a lithium cell. The problem with replacing it is that usually this is hidden away and quite difficult to get to (there is a good reason for this that is not relevant here).

    Make sure that the partition information is correct
    The other thing that has been overlooked in the advice is that there may be a minor problem with the flags in the mbr. Before making any changes to the disk, it would be worth running fdisk from a floppy and making sure that the disk has a "primary" partition and importantly, that it is marked "Active".

    What next. Well if none of the above helped, feel free to send me an email and I shall have another think. There are other things you might be able to do such as running the internal disk diagnostics running debug with an offset of C800.

    Hope this helps
  • Non System disk error doesn't always mean it's the MBR, if your laptop is 4 years old then it'll have the autodetect IDE hard drive in the BIOS, make sure it can actually see your hard drive as it may be screwed and ready for another one.
  • zainzain Forumite
    336 Posts
    Well 4 months later- i'm back and the problem is unresolved.

    I bought a new hard drive from ebay and replaced it in my laptop and exactly the same problem . So i don't think it is the hard drive and it looks like its going back on ebay.

    I have also started pulling the laptop apart in the hope of finding the BIOS battery and maybe re setting or something. Having spent a couple of hours carefully removing screws and parts , I can't find the bios battery! Where is it?

    Please help anybody!!
  • zainzain Forumite
    336 Posts
    Sorry i forgot to mention i am fairly sure it is the BIOS now because on running setup ( by pressing F2) the date and time information is all wrong.
  • Woby_TideWoby_Tide Forumite
    5.3K Posts
    Part of the Furniture 1,000 Posts Combo Breaker
    not sure entirely but is that not the CMOS(?) battery then, I'm fairly sure it's the CMOS that powers the BIOS and retains the clock settings etc. If that runs out of power then I guess it is likely that a) the date and time will reset each time and b) forget where it's HD is etc.. Is there any way you can check that? Sorry can't be more specific, I'm just going off something I read once
  • MisterT2MisterT2 Forumite
    166 Posts
    okay - so before you decide to relist the hard disk, I would have a look at one of the USB Kits such as the one that Novatch does for about £15. It can make a very good removable hard disk.
    In my previous post I said that the battery was well hidden. The reason for this is that when people protect their laptops by using a boot-up password, then you could simply reset the entire machine by removing the battery and clearing the CMOS. Newer laptops use slightly different approaches. Anyway, this is probably the reason why you are finding it difficult to locate.

    It could well be that it is a lithium cell or perhaps plugged in
    or could be soldered

    Rather than type in loads - have a look at and then go to

    If you are losing setup then the CMOS battery is dead or defunct. You could also have a m/b fault, but this is ever so (ever so) unlikely.

    Find that battery!!
  • zainzain Forumite
    336 Posts
    Thanks- I will try . Can i add the following when i change the boot sequence and try booting from floppy or CD rom it makes no difference from booting from hard drive. The message appears to have changed since the original message of 4 months ago ( why i don't know!). The new message is ' Operating System cannot be found'. I will try what you suggest.
    Thanks for your help
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