Maybe try this: http://support.microsoft.com/kb/289022

Go into Recovery Console from the install CD, and try BOOTCFG /REBUILD [edit: might be available on the command line too]

You could also try adding it manually in start->run->MSCONFIG.

Msconfig.exe in WinXp. "BOOT.INI" tab.
Win9x starts through c:\="<string_name>" in [operation systems] section. In your case the string will be c:\="Windows 98 DOS prompt".
If win9x boot files (io.sys, msdos.sys, bootsect.dos) are damaged - dunno. I know that you can install WinME after WinXp and the Xp boot manager will add WinME correctly in boot.ini. But I'm not sure about Win98/98SE.

It doesn't have to be FAT to be able to multiboot into XP/98.

I do the following: 160GB-infinity HDD. Partition and format the FIRST 120GB as FAT32. Install windows 98SE in there. When, format the rest as NTFS and install XP. They'll auto detect the 98 installation and provide a boot menu. You'll be able to do whatever you want to the FAT32 partition from within XP, but at the same time 98 will be totally unaware of the NTFS partition and XP, so there will be no problem at all.
You can even tweak the boot menu to boot into 98 by default instead of XP. 😉

Thanks for the suggestions.
All kind of things happened, but it is not fixed yet.

boot.ini is identical to my other systems where it works.
I have no CD drive on the netbook, so I made a Windows XP Recovery Console USB stick: Link. This allows me to use BOOTCFG.

I used BOOTCFG before and actually was now convinced it could fix the issue, but it just messed up: Multiple Windows XP entries selectable at startup, but pointing ot the wrong partition.

I reverted to a bad habit which I also remember from before: I booted with a DOS stick and did "SYS C:". That made the DOS prompt work again, and ONLY the DOS prompt. 🤣

Some BOOTCFG /REBUILD stuff again (and "fixmbr" and "fixboot" ), and some manual boot.ini editing. Things start to look good: I can choose XP or DOS at startup. But when I select DOS the system hangs, and I just see a blinking cursor.

Tried it again: Same thing, it results in booting just DOS, or being able to select Windows XP with a broken DOS.

Besides that:
I copied all the root files from a backup to C:. It does not change anything. File sizes and timestamps are the same.

The problem I tried to fix may not have been there in the first place: I noticed it depends on when you press F8: if you press early you can select the OS, if you press late you get the same screen but without OS selection, just LOG and Safemode stuff.

May have to accept that I just need a bootable-USB stick to get to DOS... 😒

Maybe your boot timeout is too short?

You could also leave DOS bootable, and add a CONFIG.SYS menu option to boot Windows XP.

smeezekitty wrote:

Maybe your boot timeout is too short?

The timeout was 0, that is why I used the F8 key. It is only rarely that I had any need for the Netbook to boot to DOS.

jwt27 wrote:

You could also leave DOS bootable, and add a CONFIG.SYS menu option to boot Windows XP.

Don't think that is possible, it would be like loading Windows 2000 from the DOS prompt. And I tried that in the past, for some other experiment: Something called GRUB bootloader is necessary to start windows 2000 from the DOS prompt without full reset.

Since the actual files in the root do not seem to matter much, the problem is probably outside of the file system area. So maybe it is an idea to backup the Master Boot Record area (MBR) of a similar netbook and pasting it to the problematic one? One significant difference is that one Netbook has an SSD and the other one has a normal HDD. And SSD's need to be 'aligned'.

gerwin wrote:

Something called GRUB bootloader is necessary to start windows 2000 from the DOS prompt without full reset.

Exactly, GRUB4DOS will do it 😉
Drop the exe somewhere on your harddrive and add the following line to CONFIG.SYS (bound to a menu option of course, without loading any memory managers):

DEVICE=C:\GRUB\GRUB.EXE --config-file="root (hd0,0);chainloader /ntldr"

I've been using this for years to dual-boot DOS & Windows 2000, works perfectly. If Windows ever decides to overwrite your MBR again, SYS C: will fix it right away.

Thanks,
I will try your method and my MBR idea later. This issue took to much of last evening already.

I just use Acronis to backup and restore the MBR since I use that for imaging anyway.

A boot timeout of 0 is unreliable. I would set it to something like 3 seconds and give it a run. Hitting F8 you have extremely high chance of missing it and passing it to windows
to bring up the windows startup options