drive wont boot after virus infection

[pawz]

hello folks, Gracie here again.

I have a Win 98 machine in which was infected with W32 Bropia.m and a couple of dialers. It came to me because the owners could no longer boot the machine, being told it was an invalid system disk.

I have slaved the HDD to another machine ( not this one) and cleared off the nasties, and I have scanned the disk for software errors, and when I had it slaved everything seemed in order except that it is not seen on bootup as a slave, though of course it is recognised in Windows.

As a Master it is recognised in name and size etc on the POST screen, but still it will not boot and I am told it is an invalid system disk.

I also tried fdisk /mbr but nowt came of that either.

Can you advise me as to what is wrong and how I might set it right?

Simply copying the OS over the top ( if I can ) won't fix this particular problem I don't suppose, and I would really prefer not to reformat......

 

[wolluf]

Well you could try running sys C: from a win98 boot floppy to restablish the boot sector (and check in fdisk that the partition is active - but it should be if you've been accessing it on other machine) - that not being there would cause an invalid system disk message. This might result in a boot to dos prompt (check the msdos.sys file in root of C: is there and contains expected values -

http://www.mdgx.com/msdos.htm

- beforehand to avoid this. If it doesn't, edit them in).

An install over the top might also get you up and running if the above doesn't (might need to rename win.com beforehand).

But I must admit I'd retrieve data from slaving drive, and do a clean reinstall, as suspect you might have ongoing problems otherwise (98 is easily upset!)

 

[edfair]

Haven't seen that virus, but the symptoms are of something that has moved the partition table and rewritten the boot sector to access it in the new location.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[pawz]

wolluf....I will try that on the machine I am using to slave it to. When I tried to get it to access a floppy - or a cd-rom ( yes I set them both to first boot as required) on the machine it belongs to, it ignored everything. It was late and I was tired so I left it and came on here for your wisdom before I snuk off to bed. I will have a bash and report back.

Ed, if that is so, and if wolluf's advice does not fix it, what would be the next move I wonder - but I will try the above first.

thanks to you both, champion

Gracie

 

[pawz]

Gracie back again.
Progress.
I checked and yes the partition is active. I transferred the system files successfully to C: and that got me a brief look at the Win 98 splash screen before it went to the dos prompt.

I looked for msdos.sys and found it in the Windows directory - is that where it should be??
It reported one file in there size 1646 bytes

I went to the link wolluf gave, and then to Axcel's page, but I must confess I am not clear as to what I should put in - and it is so long since I dabbled in DOS, I will have to look up how to get in to 'Edit' again. I seem to recall that there had to be a particular file or utility present on the hard disk to be able to access this facility - perhaps that was DOS 6.0.

So... that reformat looms closer....

 

[pawz]

ps. If it continues to be recognised when I next spin up I will try running the OS over the top - that'll larn it. I hear what you say about storing up difficulties wolluf, it might yet come to a reformat, but I will try this way first

cheers

Gracie

 

[edfair]

Your msdos.sys should be in the root, as a SHR attribute file with the first couple of lines being the pointers to where the windows files are stored and a line near the bottom of the text telling it to boot in GUI mode.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[pawz]

I found out why the flop wasn't working on the owners machine - someone had been in setup and changed the two floppy drive options to the wrong size.

Anyway, I have run the OS over the top and all is well now, except on one bootup nothing came on the screen and I had to reboot - but maybe that was just a passing glitch.
At present PCPitstop is checking it for viruses, but hopefully that will be clear and I can take it back tomorrow...

thank you for your help peeps, much appreciated.

Gracie