If I remember correctly the difference between U.S. OEM vs Upgrade Windows 98 was just four files. When I used to fix computers I identified them by comparing both install CDs. I ended up making my own W98 install CD with those 4 extra files in a separate folder that I would copy over when I had to do a clean install.

If you really need those 4 files and unable to locate them online, PM me and I will try to help you.

TL;DR No, you need OEM install CD or, at least, 4 files from it.

PS I also "vaguely remember" with some upgrade versions you'd have to insert a disk with your previous OS during install to prove your eligibility for upgrade.

Jade Falcon wrote:

Is there a way to clean installing 98se with an upgrade disk?
I vaguely remember a way to do that, but might be remembering wrong.

I think so, though I'm not sure whether there are any exceptions.

Usually it would be possible to start installing and after a while the installer would ask for proof of you having an older OS by asking you to insert an appropriate installer disk into the optical drive (iirc this disk must be a full version though).

StSam wrote:

If I remember correctly the difference between U.S. OEM vs Upgrade Windows 98 was just four files. When I used to fix computers […]
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If I remember correctly the difference between U.S. OEM vs Upgrade Windows 98 was just four files. When I used to fix computers I identified them by comparing both install CDs. I ended up making my own W98 install CD with those 4 extra files in a separate folder that I would copy over when I had to do a clean install.

If you really need those 4 files and unable to locate them online, PM me and I will try to help you.

TL;DR No, you need OEM install CD or, at least, 4 files from it.

PS I also "vaguely remember" with some upgrade versions you'd have to insert a disk with your previous OS during install to prove your eligibility for upgrade.

Which 4 files are the ones needed for such a thing?
I guess it beats having to insert an older OS's disk during install 😁

If you have the first disk of an Windows 95 installation on floppy disk you can put it in the drive and it will actually see it and you should be good for the upgrade. The same thing works with MS Office with a version 4.3 floppy and any upgrade up to Office XP and possibly newer I just haven't tested.

Sorry about delayed reply. Had to find my W98 combo install CD.

Looking at it, I have 2 sub-directories I've made that contain the files that differ between OEM and Upgrade.
Normally I'd copy the contents of the corresponding folder into main install directory, overwriting existing file(s).

UPG:

PRECOPY2.CAB

OEM:

PRECOPY2.CAB
FORMAT.COM
OEMSETUP.BIN
OEMSETUP.EXE

Note that PRECOPY2.CAB files are not the same.

StSam wrote:

Sorry about delayed reply. Had to find my W98 combo install CD. […]
Show full quote

Sorry about delayed reply. Had to find my W98 combo install CD.

Looking at it, I have 2 sub-directories I've made that contain the files that differ between OEM and Upgrade.
Normally I'd copy the contents of the corresponding folder into main install directory, overwriting existing file(s).

UPG:

PRECOPY2.CAB

OEM:

PRECOPY2.CAB
FORMAT.COM
OEMSETUP.BIN
OEMSETUP.EXE

Note that PRECOPY2.CAB files are not the same.

Thanks, I saved your reply offline for future reference 😀