HEY ALL, trying to fix my kids' school computer.

It's a dinosaur but still seems to serve their purpose.

anyhow, during boot process , system stops with an "invalid system disk "
"replace and try again" . There is no floppy in the drive. I've tried
bypassing the floppy (unplugging and disconnecting power and ribbons) and
changing bios to boot from c: drive first but still getting the same
message.

I've tried using a windows 95 startup disk but floppy light goes on and
it just hangs there , when the start up disk comes out same old message
appears.

I have also tried using another controller card hdd &fdd with same results.

I have also tried a different floppy drive with same results.

the system does go throught the memory test and I do get one beep for
the motherboard but thats where she stops.

any suggestions.
appreciated

When you go into the BIOS setup, do you see parameters for the hard drive?
Can you hear the hard drive spin up?

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reido@my-deja.com

Originally posted by Reid:
When you go into the BIOS setup, do you see parameters for the hard drive?
Can you hear the hard drive spin up?


yes I do hear the hard drive spin up and there are parameters for the
hard drive......47=user type...etc.

Well, I'm stuck without ideas at this time. If it would boot from a floppy, we'd be getting somewhere. It may help if you can provide the name and number of the BIOS that comes up on the screen. I'll keep pondering this one. Anybody else have ideas?

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reido@my-deja.com

[This message has been edited by Reid (edited 01-03-2001).]

sorry reid,

I reset the cmos values back to original. When I turned on the pc I received a flashing message " chipaway virus warning" and below that a message .." boot disk is infected by virus"......"system halt".
There was no floppy in at the time.

I then rebooted using a newly created win95 boot disk. I got the starting
windows95 line but ended up only at a:\ prompt. I could not access c: drive.
I ran a western digital hard drive utility which concluded that hard drive
surface had no errors, and a bios diagnostic that stated system bios could
not access all of the hard drive.

If my boot sector is corrupt is there a way I can still access the hd and
retrieve some important info.
thanks for your efforts

Just a wild shot ......

Maybe you need to fdisk and format your harddrive again.

[This message has been edited by greenhornet (edited 01-03-2001).]

Trend Chip Away FAQ (http://www.antivirus.com/products/chipaway/faq.htm) says: Trend CAV is antivirus code that is embedded within the system BIOS. It is the most convenient and effective way to prevent computer boot virus infections.

It sounds like the built in BIOS virus protection has found one. Run a good virus scanner with current DAT files and see what it comes up with. Since you're having trouble booting you might need to try an emergency disk.

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My hairdresser charges me a finder's fee!!

Please post your questions on the forums, not in my email.

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I created an emergency disk but virus pattern disks and booted the system.
It prompted me through the whole series of disks . Net result was no
virus found in system.

The system was shut down incorrectly a number of times before all this
happened Would this result in the boot sector being messed up.

Once again the hard drive is being recognized in the bios but cannot access
it otherwise. When I try through dos, I get invalid drive specification.

bios is .....AMIBIOS ..INICHIP BIOS VER 2.0A

Computer Associates FAQ had this procedure, which is commonly used to restore the boot record, but I had not thought about it before in the case of where a virus is involved:

FDISK /MBR
MS-DOS 5.0 or higher: If you have MS-DOS 5.0 or higher, you can use the DOS command FDISK /MBR to remove all viruses which infect the master boot sector and which do not encrypt it. This option should be used only when all other attempts to repair have failed. Using FDISK /MBR can sometimes produce unexpected results, causing unrecoverable damage to your system.

Here's how to do it:
Power off the machine.
Place a clean, write-protected system disk in A: drive, and then power on the computer. NOTE: For this option to work correctly, you must boot from the same version of DOS that is installed on the hard drive. Using a different version of DOS could adversely affect the system information on your hard disk.
From the A: prompt, type: C:\DOS\FDISK /MBR and then press Enter.
Power off the computer when you see the prompt again. (You will normally see no message from the command in the previous step.).
Restart the computer normally, and then scan with your anti-virus software to verify that the virus is gone.
**************
I was going to recommend the free F-Prot DOS antivirus program, but it no longer fits on a floppy. There is a way to format a floppy to 1.72M, which is then readable after loading a small file, or a RAMDISK could be created to hold the files.

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reido@my-deja.com

Regarding my last post, if you have access to a Windows 98 Startup disk, if you boot with it, you can delete the files from the 2M RAMDRIVE it creates (one drive letter after the last hard drive), then copy the antivirus program files there.

You could also make your own RAMDRIVE. See MS-DOS Memory Advanced (http://www.frick-cpa.com/dos/DOS_Memory_2.asp) on how to use RAMDRIVE.SYS.

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reido@my-deja.com

well as for the fdisk/mbr I am not there yet. Not sure I understand the
procedure all that well.

some new info... fdisk reveals. 1 partition ...active ...non dos...no volume label....3095 mbytes....nothing under system....100% for usage

and disk space is 504 megabytes.

windows98 does create ramdrive but uses the letter c:
when booting via win98 .... states no valid fat or fat32 partition

also what is the purpose of running the anti-virus program of the ram drive
sorry don't quite understand...

addendum
fdisk
shows available space of 504 meg but it is actually

3.2 gig hard drive...

tell me I don't have to format this thing

I recently had a couple new systems brought into the shop - one had a maxtor overlay (DDO) put on the hard drive and immediately brought up Trends ChipAway virus warning...Trend told me that it was "outdated" and to disable virus protection feature in their bios (they didn't even ask if I had other virus protection until after they advised this disable...apparantly they know alot about false warnings)
Once the DDO was removed the non-dos was set to dos partition in fdisk...
Can you remove your DDO..if one was put on before you got it?

If your running a 3.2gb disk on a 486 then it's probably using disk overlay software, right? The fact that the disk is showing as 504mb suggests that the overlay is defective (?) as 504mb is probably the maximum harddisk size for a computer of this age. If you don't have this overlay software you might check around the drive manufacturer's website for it. Usually you install it on a bootable floppy and run it from there... there are often utilities for disk maintenance, or perhaps to re-install the overlay... I'm groping here, but it's at least worth a look.

[This message has been edited by sleddog (edited 01-03-2001).]

Originally posted by KAZOU:

also what is the purpose of running the anti-virus program of the ram drive
sorry don't quite understand...



Not too many years ago, some DOS antivirus programs would fit on a single floppy, but the definition files have gotten larger because the number of virus' have increased. If the hard drive is inaccessible, as in this case, there needs to be another way to load an antivirus program such as F-Prot, but the necessary files take about 1.8M (so even the 1.72M floppy would not work). The files could be put on two floppies, then copied to, and run from, the RAMDRIVE.

I agree with the drive overlay ideas. A 486 would be limited to running a 540M drive without one, and sometimes they are detected as a virus.



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reido@my-deja.com

BINGO ...

Thanks to all for all the input and for setting me in the right direction

I downloaded some harddrive utilities from western digital.....and the
ez-maker utility did the the trick. I was able to change the bios to accept the larger drive and that did the trick. The whole process has been
quite frustrating given all the weird error messages that were leading to
viruses ...etc

anyways...thanks a bunch once again to all respondents. This hack will do his best to return the favor even though there is an abudance of masters
here. http://www.PCGuide.com/ubb/biggrin.gif http://www.PCGuide.com/ubb/biggrin.gif