Internet Explorer 6 SP1 fails to install (Unknown error)

[tsautier]

What is happening?

The installation of Internet Explorer 6 Service Pack 1 fails when using Legacy Update.

During the “Performing Actions” phase, the process stops and displays the following error:

“Internet Explorer 6 Service Pack 1 failed to install. Unknown error (error)”

The update appears to download, verify, and extract correctly before failing without any detailed error code.

What should have happened?

Internet Explorer 6 Service Pack 1 should install successfully without errors and complete the update process.

Steps to reproduce the issue

1. Launch Legacy Update
2. Start the installation
3. Wait until the “Performing Actions” stage
4. The installation fails with an unknown error

Operating System

Windows 2000

Service Pack

SP4

Architecture

32-bit (x86)

Virtual Machine

Yes, VMware

Hardware

Not applicable

Software Installed

Not applicable

Other details

• Legacy Update version: 1.13
• The installer progresses through downloading, verifying, and extracting before failing
• No detailed error code is shown

Confirmation

• I have checked that this issue hasn’t already been reported

[tsautier]

From LegacyUpdate Logs :

2026-03-17 16:44:13	Setup[1028]	Legacy Update 1.13
2026-03-17 16:44:13	Setup[1028]	OS: 5.0.2195 Service Pack 4 x86 (Workstation, Suite: 00000)
2026-03-17 16:44:13	Setup[1028]	Command line: "C:\Documents and Settings\Administrateur\Bureau\LegacyUpdate-1.13.exe" 
2026-03-17 16:44:13	Setup[1028]	Admin, n/a integrity
2026-03-17 16:44:14	Setup[1028]	Downloading Update Rollup 1 for Windows 2000 Service Pack 4...
2026-03-17 16:44:15	Setup[1028]	Verifying Update Rollup 1 for Windows 2000 Service Pack 4...
2026-03-17 16:44:15	Setup[1028]	Downloading Internet Explorer 6 Service Pack 1 Setup...
2026-03-17 16:44:16	Setup[1028]	Verifying Internet Explorer 6 Service Pack 1 Setup...
2026-03-17 16:44:16	Setup[1028]	Extracting ...
2026-03-17 16:44:16	Setup[1028]	Execute: "C:\WINNT\system32\expand.exe" -F:* "ie6setup.cab" "C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\nsh3.tmp\IE6"
2026-03-17 16:44:16	Setup[1028]	Exit code: 0
2026-03-17 16:44:16	Setup[1028]	Downloading Internet Explorer 6 Service Pack 1...
2026-03-17 16:44:16	Setup[1028]	Execute: "C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\nsh3.tmp\IE6\ie6setup.exe" /c:"ie6wzd.exe /q /d /s:""#e"""
2026-03-17 16:44:16	Setup[1028]	Exit code: error
2026-03-17 16:44:16	Setup[1028]	Unknown error (error)

[tsautier]

I manually downloaded the package by digging around in the LegacyUpdate temporary files: http://download.windowsupdate.com/msdownload/update/v3-19990518/cabpool/ie6sp1-wucab-fra_0bc4219b3119a127503cd93863cfedfb1e37bd55.cab, I can execute the command line from the log file without any problem, but LegacyUpdate doesn't see the patch installed (same after reboot too).

[tsautier]

A minor, cosmetic detail to fix: the logs in Windows 2000 are located in C:\WINNT\Temp\LegacyUpdate.log and not C:\Windows\Temp\LegacyUpdate.log

Maybe use %WINDIR%?

[tsautier]

Hmmm something :

I thought it had installed IE6 correctly, but not at all! This time I ran ie6setup.exe without any arguments and followed the steps to the end; it automatically restarted my VM (which wasn't the case with arguments in the CLI), and now Internet Explorer no longer appears when I run Legacy Update.

[kirb]

The IE6 setup is run in two phases - the first downloads the files, and the second installs them. The command line you ran was for the download phase.

Were ie6setup.exe and iebatch.txt extracted to the desktop by Legacy Update? If so, that would be the issue - they’re supposed to be going to the temp folder.

Good point about the logging page, I’ll see about correcting it while trying to keep it simple enough for people who might not be familiar with environment variables.

[tsautier]

No, it was me, I did the extraction on the desktop.

I think the failure is in setup/DownloadIE.nsh, not the actual IE6 install step.
The failing command matches setup/DownloadIE.nsh line 20, not the install step on line 29.
So the error happens during the IE6 download/prestage phase (/d), before the actual install phase (/r:n).

[renodr]

I'm able to reproduce it on a fresh installation of Windows 2000, removing the Needs triage label and pinning it