This is a mirror page and updated only once in a while. Original post follows.
Microsoft has never released a service pack for Windows98 SE but this contains all Windows98 SE updates from Windows Update site and more.
This project has been taken over by a new person due to illness from the original author. Visit the author link above if you need help. This download originally had 811,251 before it was taken over by a new developer.
Before installing U98SESP3.EXE make sure that:
1/ You have the original w98SE installation disc.
It will change core system files. It means that if something goes wrong you must be
prepared to reinstall windows from the beginning.
Sometimes installing U98SESP3.EXE after a fresh install is working normaly while it failed on an old install.
2/ You made a backup of all important data.
It’s extremely unlikely that an error forces you to re-install windows and
eventually to reformat thus to erase your hard drive.
But for the sake of safety, please do it!
3/ You made a backup of your system files
A copy of the “Windows” and “Program Files” directories, at least the “Windows” directory,
preferably on a second physical hard drive or CD or DVD or an external drive.
This is useful to revert to a previous w98se install which was already
updated and functioning well.
Restoring Windows 98 can be done simply be recopying all the system files back to their original location, in dos mode. The easiest way is to use a second physical (not a partition) and internal (not USB) hard drive.
It’s also a good idea to make sure a copy of the registry has been automatically preserved in the system files you backed up and to know how to restore the registry in dos: boot in DOS, then type SCANREG /RESTORE.
4/ You have time and patience to read all the instructions
If you are somebody, who will select all options no matter what they are or who will click “OK” instead of “Cancel” on any dialog box without knowing what was the question about, then you are sure to run into trouble.
5/ You have read the disclaimer below.
The author and owner of this website as well as the owner of the server hosting this website
and all the persons having been involved in the creation or the distribution of the files, updates, and executables present on this website will not be responsible for any material damage, loss of hardware performance or functionality, alteration or loss of data, theft of data,
exposure of classified documents, loss of privacy, penalty, material or financial depreciation or loss or liability or any other loss or damage or liability of any kind caused by the use or inability to use these files, updates or executables.
They are delivered to You for free, as is and without any warranty attached beyond those already
described in the agreements between You and their authors or vendors if any. You understand that most of them don’t come with any warranty at all and that there is no guarantee that they will work on your computer as advertised.
Moreover, you agree to use each of them with respect to the user agreement provided by their author if any.
Use at you own risk.
More specifically, You understand that the author and the other persons who participate in its creation, promote, advice to use, or distribute the Unofficial Windows 98SE service pack (U98SESP3) known as U98SESP3 or as U98SESP3.EXE or any other denomination used for translated versions or further updated versions, as well as Microsoft Corporation or any other party directly or indirectly concerned, will not be liable for any damage, loss of software or hardware functionality or performance, loss of data, loss of time, loss of money or any loss or liability of any kind caused by the use or inability to use U98SESP3.
You understand that U98SESP3 is not a product of Microsoft Corporation and not a product of a commercial company, that’s it’s developed and distributed as is, benevolently, unofficially (although legally) and freely without any guarantee attached, without any promise of support,
that there is no guarantee whatsoever that it will work as advertised and that you use it
at your own risk and in full consciousness of the risks attached to an unofficial service
pack for an operating system.
Before installing U98SESP3 You are supposed to have made all the necessary steps to safeguard your data and be able to reinstall an operating system as described in, but no exclusively the important notice above and to have the technical knowledge and ability to fix computer
related problems in the case U98SESP3 will prevent your computer to work properly.
These necessary steps consist in, but no exclusively:
– Having the original w98SE installation disc
– Making a backup of all important data
– Making a backup of the system files
– Having a backup of the registry
Before, during and after the installation you are supposed to read CAREFULLY all the instructions
you get through dialog box messages, dos prompt messages or otherwise.
Version History for Unofficial Windows 98 Second Edition Service Pack: