Crashed.

What OS ?
Anyway, try safe mode boot, F8 while booting. Then try to find if your datas are still alive...

If so, you can choose between :
- re-install OS in same directory (won't loose your application, but may have same bug)
- Put drive in slave mode in another computer, just to copy datas. Then fdisk, break partition, re-format, and re-install, hoping Hd fault won't re-appear.

Try the safe mode bootthen once in safe mode and it is a newer operating system(IE win me or later)
try going to accessories/ system tools/ system restore this should take you back to the last good system date. Its worth a shot.

All she did was to leave it on? Was there anyone there to tamper with the computer during the time she left? If all she did was leave it on then one of two things probably happened. 1) The unit over heated severly and something is damaged. Could be the hard drive or could be the CPU. 2) There was a severe power surge and now the power supply is damaged. We need more info on what happened and symptoms. Did she power off and power on to reboot? She would have to use a boot disc to help resolve the problem but honestly from what you say she will need far more hand holding to fix the problem because she obviously has no idea about computers. I strongly advise she find a friend who is more able to understand loading up a boot disc or doing safemode checkout, or going into the BIOS. It sounds to me that telling you what to do here may confound or confuse the problem. Is this computer under warranty? How old is it. If it is not an old computer (a year or less old) she should not buy a new one but get this one fixed.

I agree with donmars...from the vague info, I would say the HDD is dead. Depending on specifics, could be PS, mobo or whatever. She should definitely take it to a professional (of course be careful not to get shanked). If under warranty, that much better. Anyway, that's my 2 cents worth. Good luck!

Point value changed by question poster.

Further information:

She always leave her pc on during the day, but switch it off at night and it has a timer for standby mode if she doesn't use it for a while.

When she first switch the pc on, this sign shows up in DOS mode:

"Operating System not found"

When she switch pc on with ME Edition start up disk, the screen shows:

"Microsoft Windows ME Startup Menu.
1. Help
2. Start computer with CD Support
3. Start Computer without CD Support
4. Minimum Boot.

She tried to type no. 4, but get this;

Mode Prepare cable function coupled
Mode Prepare cable function coupled

A:>

What is required at the "A:"?

She found an introduction from the 'library' at PC World and they said You should press no. 4, type scandisk/all, entre and then sys c:. Afterwards, you should take the start up disk out and press ALT+CTR+DEL. However, when she tried to type sys c:, there is a sign that said:

"Cannot find the system file in the standard locations on drive c: SYS can only be used on drive c: to attempt a repar of an already existing installation of windows. Use SETUP to make drive c: bootable"

So how can she use windows Setup?

If you're running 95-98x use a 98 boot disk and do a scandsk to see if there are errors on the disk. If the HD is not accessible (starts and stops) Your hard drive may be shot. If this is the case you still may recover some of the data from it. First take the HD out, place it in a Zip Lock Bag and put it in the freezer for a few hours. This will keep the chips cold enough that before they warm up you glean some of the data off of it. You may have to perform this task a number of times.

She doesn't need a new tower just a new HD

Operating system not found means just that. It also means the hard drive is working mechanically. The system found the boot device, hard drive, but could not start the operating system. The OS (operating system)startup files have become corrupted. In many cases it is not the hard disk itself but rather an external factor that is causing the problem. One cause? Many viruses act against the file system. It is a simple thing for a virus to change the disk's major structures so that it appears empty or invalid. Virus scan from the DOS prompt, thats what "A" is by the way,The drive the boot floppy is in is the "A" drive, would be cumbersome for you because of your level of computer knowledge. Since you do not know what "A" drive is then its best we take the easy route on this one, although a good virus scan is recommended here! 1)From the A: prompt Type C: then enter. 2) If you get to C:, type cd windows and then hit enter. 3) type cd command then enter. 4) type scandisk then enter. This may or may not work. If it does then follow the the prompts and let the program fix everything. Dont worry about saving anything or making an undo disk, just go through the routine to the end, performing all the tests. If this fixes your problem thenyou need to run an updated virus scanner.

You could try reinstalling the OS if the above does not work.
1) At the A: prompt type format c: Format the C: drive and at the end reboot with the boot floppy then enter 2 to Start computer with CD Support. After computer boots place CD in CD drive. Go to the cd drive, which should be E: (the boot disk uses "D" as a ram disk) So type E: at the A prompt. type setup and let the system install. From your questions this will be a puzzling experience for you but think of how much you will learn, just go slow read, observe and think.

This question was closed by the author