Thanks, madmonkey. The file system is NTFS. NTFSforDOS shows all is there (permissions now changed to EVERYONE, to be 101 % sure). Been trying to reach to winnt.exe via NTFSforDOS but, like you say, it´s hard to get to the installation program from there. I still get "invalid drive specifications" both when typing C:\> only and when tryng to reach to the installation program.
Is there perhaps a way to change he file system to FAT32?

Ok, so I finally managed to get to the installation program by the NTFSforDOS floppy and loading smartdrv from the boot98 floppy, then by typing C:\CDROM\i386\winnt.exe. All seems fine...
When the setup program asks me where the installation files are to be found, i type C:\CDROM\i386 - and I get an error mesage :-(
says bootloader cannot be found (it´s a Norwegian version and I THINK oppstartsfiler translates to boot loader files)

err, not sure there karin to be honest, I've not done it via NTFSforDOs before.

Two options then,
You can either put the disk back in your son's PC, and format as FAT32 under Administrative Tools, Computer Management, Disk Management. And then copy the installation files back. This time though, put everything into the root folder and not the CDROM folder, just incase part of the setup is looking for \386. I'm sure I've done it the same way as you in a seperate folder, but just in case.

Or.. I could try this on a test PC, to see if I can find a workaround. But I won't be back at my workshop until Wednesday to look at this?

I´m on kindergarden level with this... So, where do i find the root folder or, how do i create a root folder? May I just create a folder and call it "root"?

Sorry, it's me, nobody ever understands me when I say root. Think of a tree. It's the c:\ so your structure will look like
c:\setup.exe
c:\i386\..

No, not you (LOL), it´s me not being into the terminology! Low geek-factor here :-)
I will try again but, I´m a bit pessimistic. I did try that weeks ago, copying all from the CD-ROM to the equivalent folder on hard disk (overwriting existing content) in an attempt to replace what had been erased by the spyware/virus. The computer still would not boot.
Scanning by NTFSforDOS says there are 24 kb in damaged sectors. Scanning by use of other computers, USB attaching this hard disk, finds no physical damage. I will try again and post back when done.

Well, ok, I have given up trying to make the laptop work that way. It won´t change the file system from NTFS to FAT32 (no option given, although the host laptop I use for mending the messed up drive has FAT32), it will just format the disk.

Did a net seach and found that FAT32 could be converted to NTFS (as I did 3 years ago - I deeply regret that now) and that it is not possible to reverse NTFS to FAT32. A one way go :-(

I did copy the installation CD onto the disk about a month ago (before I sought help in thsi forum), each file and folder to root, not one separate folder (did that later) - but, windows would not boot up, no matter what I tried.

Which brings me back to the original question: is there a way to make an image file of the installation CD files that will boot up when the system starts? Just like the so-called "pre-installed" computers, where nothing is installed until the computer boots up, but installs from an image file? Will I then have to make a new partition to place this installation image in?

Another question: This installation CD is a OEM licence that came with the computer. Will it work at all if I try install with the CD files on a new bigger hard disk replacing the old original harddisk?

Or, you may perhaps, perhaps have time to find a workaround on an NTFS system for me?
(I know you help out many more un this forum, and I really don´t want to occupy too much of your time. I´m very, very grateful for the time you´ve taken with me and my case so far).