In This Chapter

Removing Internet Explorer Core Files

Understanding the Uninstall Process

Using Maintenance Mode ACME Setup Errors Files Used by Uninstall Registry Entries Used by Uninstall Deleting Uninstall Files

Understanding the Uninstall Log

Understanding Emergency Uninstall: IERemove.exe

Removing Internet Explorer Core Files

As explained in the previous chapter, there are two Add/Remove dialog boxes used by Internet Explorer, each with distinctly different functionality. The first dialog box is the traditional Add/Remove Programs applet in the Control Panel. This is used to uninstall only Internet Explorer add-on components with corresponding .inf files containing uninstall information. This is not used to uninstall the Internet Explorer core files. (For information on removing add-on components, see Chapter 6, "Adding and Removing Components After Setup.")

The second dialog box appears when Microsoft Internet Explorer 4.0 is selected from the software list in the Add/Remove Programs dialog box, and the Add/Remove button is clicked. This dialog box is displayed by Setupwbv.dll, which knows how to invoke Maintenance-mode ACME, call an .inf file uninstallation, or launch Internet Explorer to download new components from the Web.

To uninstall Internet Explorer

1. In the Control Panel, double-click the Add/Remove Programs icon. 

2. In the software list, click Microsoft Internet Explorer 4.0, and then click the Add/Remove button. The resulting dialog box will present you with three options. The first of the three options is used to uninstall core files and any add-on components you select. 

    

3. Select Uninstall Internet Explorer 4.0 and all its components, and then click the Advanced button. 

    

4. In the resulting dialog box, select Uninstall Internet Explorer 4.0 and the components selected below, and click the check boxes next to the components you want to uninstall. 

For each component, the registry contains a minimum version and an Internet Explorer build number with which the component will work. For example, one component may work if Internet Explorer 3, build 1155, or greater, is installed. Another may only work if build 1300, or greater, is installed. Some only work if Internet Explorer 4 is installed. Setup recorded the previous browser version in the registry when Internet Explorer was installed. That value is compared to the version requirement of each component. If the previous version is less than the required version of the component, the component's box will be checked.

Warning In the Advanced Uninstall dialog box, if you select Delete the backup information for Internet Explorer 4.0, you will delete the IE4bak.dat, IE4Bak.ini, Integrated Browser.dat, and Integrated Browser.ini. files, which contain important uninstall information that you will need if you decide to reinstall and uninstall Internet Explorer again. It is recommended that you not delete these files. (For more information, see "Deleting Uninstall Files" in the next section.)

For troubleshooting information about removing Internet Explorer 4, see Appendix B.

Understanding the Uninstall Process

ACME Setup is used to uninstall Internet Explorer 4 core files, whereas the Internet Explorer add-on components use the standard .inf method of uninstallation, as per Windows 95 and Windows NT compatibility specifications.

ACME Setup relies on the following files:

• C:\Program Files\Internet Explorer\Setup\Setup.stf 

• C:\Windows\IE4bak.dat 

• C:\Windows\IE4bak.ini 

• C:\Windows\IE4RegUn 

• C:\Program Files\Internet Explorer\Uninstall\AINF0000 

• C:\Program Files\Internet Explorer\Uninstall\Integrated Browser.dat (if the Integrated Browser is installed) 

• C:\Program Files\Internet Explorer\Uninstall\Integrated Browser.ini (if the Integrated Browser is installed) 

If, for some reason the .dat and .ini files are damaged or missing, the user may be able to get them from another system and successfully complete the uninstallation. Keep in mind that both systems must be running the same operating system, must have chosen the same Internet Explorer installation option, and must have had the same browser installed prior to installing Internet Explorer; and that the install path for each browser must be the same.

The registry information needed to uninstall is stored in the AINF0000 files. Installation instructions for each component includes the RegSave function, instructing Advpack.dll to move data from the registry into the AINF0000 files. During uninstallation the RegSaveRestore function is called, the AINF0000 files are loaded into the registry as hives, and the registry is updated with the original data. Similarly, an IE4RegUn file is created under the Windows folder, which contains backed-up registry information for the Internet Explorer core.

You should remove Internet Explorer 4 before performing any of the following actions:

• Installing an earlier version of Internet Explorer. 

• Restoring a registry (System.dat or User.dat) that was created before you installed Internet Explorer 4. (This applies to Windows 95 operating systems only.) 

• Using a Windows NT Emergency Repair Disk (ERD) that you created before you installed Internet Explorer 4. (This applies to Windows NT operating systems only.) 

• Upgrading to a later release of Internet Explorer 4. 

• Reinstalling your operating system (Windows 95 or Windows NT). 

• Installing or uninstalling operating system upgrades (for example, Windows 95 Service Pack 1). 

Uninstalling does not support the following versions or situations:

• The beta 2 version of Internet Explorer 4 installed over a previous version of Internet Explorer 4. 

• The final version of Internet Explorer 4 installed over a previous version of Internet Explorer 4, other than beta 2. 

• Internet Explorer 4 installed under multiple operating-system installations (Windows 95, OSR2, or Windows NT 4.0) on the same logical drive. If you need to run Internet Explorer in multiple operating systems, you must install each operating system to a separate logical drive letter. 

• You have removed the Internet Explorer 4 backup files. If you removed these files, you cannot uninstall Internet Explorer 4 without reinstalling Windows to a different folder. 

Uninstalling does not completely return your computer to its previous state. It leaves behind some files, registry entries, and shortcuts. Additionally, some user settings are not restored with the previous version of Internet explorer. System files such as Setupapi.dll are left behind to support other .inf file installs, or OLEAUT32 to prevent breaking OLE functionality in Office. For a complete list of files that uninstalling does not delete from the system, see Appendix A.

Because of the larger number of changes made to the system by Setup, a manual uninstall would require many, many steps and a great deal of time. Attempting a manual uninstall is not recommended.

For the latest list of issues you need to be aware of while running Setup and while uninstalling, check the Internet Explorer 4 Readme file.

Using Maintenance Mode ACME Setup

Uninstalling relies on the existence of this registry key:

HKEY_LOCAL_MACHINE \SOFTWARE \Microsoft \Windows \CurrentVersion \Uninstall \IE40"C:\ProgramFiles\InternetExplorer\Setup\SETUP.EXE"/gC:\WINDOWS\IE4UninstallLog.txt 

This value launches maintenance-mode ACME Setup with hands-off operation.

Uninstalling also relies on the following back up files: IE4bak.dat, IE4bak.ini, Integrated Browser.dat and Integrated Browser.ini. If these files are missing, uninstall will fail. Note that the Integrated Browser files are only needed if the Windows Desktop Update is installed at the time of uninstallation.

After maintenance mode, ACME Setup uninstalls Internet Explorer. The Setup folder will remain on the system so that Internet Explorer may be installed again without requiring connectivity to the Internet.

If the User Profiles option has been enabled, Setup will ask if you want to remove Internet Explorer settings from your user profile (User.dat).

You can also run maintenance-mode Setup manually, by running Setup.exe from the Setup folder in your Internet Explorer installation folder. To be in hands-off mode or to create an uninstall log file (IE4unin.txt) you will need to specify the following command line:

C:\program files\internet explorer\setup\setup /g C:\ie4unin.txt

Or, if you don't have long file-name support:

C:\progra~\intern~1\setup\setup /g C:\ie4unin.txt

Errors

If Shell32.dll and Explorer.exe are not successfully extracted from the Integrated Browser.dat, the newer versions of those files will still load, and you'll be presented with this message:

The SHLWAPI.dll made a bad call to Explorer. 

To fix this, extract the original versions of Shell32.dll and Explorer.exe from your Windows CD-ROM and copy them to the system, overwriting the newer versions.

Files Used by Uninstall

There are several key files needed for a proper uninstall:

Setup.exe Runs the ACME Setup program.

Setup.stf Contains instructions for the ACME portion of Setup or uninstallation and calls IE4.dll.

IE4.dll Custom Action Setup engine used for logging and for custom file or registry additions, changes, or removals.

IE4.inf Contains instructions for IE4.dll.

Advpack.dll Used for Internet Explorer Express cabpack extraction, and for .inf file parsing or execution while uninstalling programs installed with Internet Explorer Express. Used in combination with W9INF32.dll and W9INF16.dll on Windows 95 systems.

Setupapi.dll Originally a Windows NT file, Internet Explorer uses this file in both Windows 95 and Windows NT for locating .cab file and .inf file installations.

Integrated Browser.dat Contains Integrated Browser modes files, including the previous versions of Explorer.exe and Shell32.dll, and is used for installing or uninstalling the integrated browser mode. This file is called Integrated Browser NT.dat on the Windows NT operating system.

Integrated Browser.ini Contains information about Integrated Browser.dat.

IE4bak.dat Contains many of the files needed to uninstall Internet Explorer.

IE4bak.ini Contains information about IE4bak.dat.

Setupwbv.dll Used to control mode switching by parsing IE4Shell.inf and calling Advpack.dll for IE4shell.cab extraction.

IE4shell.cab Contains new shell components and is used in mode switching and uninstall.

IE4shell.inf Contains instructions for mode switching. Also contains the contents of IE4shell.cab.

IE4data.inf Contains instructions for uninstalling data components.

IE4data.cab Backup file for data components used during installation and uninstallation, and that rely on Internet Explorer (Task Scheduler, ActiveMovie, Multimedia Controls, etc.) This file is called by Advpack.dll.

There are several other uninstall .inf files; one exists for each external component. All are called using Advpack.dll.

Registry Entries Used by Uninstall

There are several registry keys that need to be present and populated for proper uninstalling:

HKEY_LOCAL_MACHINE \SOFTWARE \Microsoft \Windows \CurrentVersion \Uninstall contains entries for everything that shows up under Control Panel Add/Remove Programs and some that do not. Each item listed has its own method (command line) for launching an uninstall. Note that entries containing a QuietUninstall key refer to external components (.inf files) called during an Internet Explorer uninstallation.

HKEY_LOCAL_MACHINE \SOFTWARE \Microsoft \Windows \IE4 \Options contains location and other info for IE4bak.dat and 4bak.ini.

HKEY_LOCAL_MACHINE \SOFTWARE \Microsoft \IE4 \SETUP contains some miscellaneous file location information for various logs, etc.

HKEY_LOCAL_MACHINE \SOFTWARE \Microsoft \IE4 \SETUP \History contains information concerning previous browser information.

HKEY_LOCAL_MACHINE \SOFTWARE \Microsoft \IE4 \SETUP \IE4RegBackup contains backup registry information saved by Setup. The 0 section contains the actual data, and the 0.map contains table-of-contents type tracking of the information in 0. In cases of reinstallation and upgrade, the *.map keys (starting with 3.map and incrementing by 1 per reinstallation) are created to track differences.

HKEY_LOCAL_MACHINE \SOFTWARE \Microsoft \AdvancedINFSetup \IntegratedBrowser \RegBackup contains 0 and 0.map sections used to back up and track registry information used to uninstall the Integrated Browser. Map files are not created in this section, and the 0 and 0.map sections should be empty if Integrated Browser mode is not enabled.

Deleting Uninstall Files

If you delete the primary uninstall information (IE4bak.dat, IE4bak.ini, Integrated Browser.dat, Integrated Browser.ini), you will see this message if you reinstall:

After the reinstallation is complete, you may have options disabled in the Advanced Add/Remove dialog box.

Understanding the Uninstall Log

The most important tool for troubleshooting an uninstallation is the uninstall log, called IE4 Uninstall Log.txt, located in the Windows folder. This log is very comprehensive. It covers the entire uninstallation process sequentially from beginning to end, including every file addition or removal; every registry addition, change, or removal; and any dialog boxes shown to the user. The log is divided into Passes which denote the different phases of an uninstall. Entries in the log also have an Object number — which corresponds to the line entry in Setup.stf. Lines without an Object number result from custom actions specific to Internet Explorer 4 — and are contained in the IE4.inf file or in an .inf file from an external component uninstallation. The Uninstall Log is not created when IERemove.exe is run.

Understanding Emergency Uninstall: IERemove.exe

IERemove.exe is not a separate uninstall program. It is a forced removal of the Internet Explorer core. It should be used only in circumstances where the Add/Remove Programs applet in the Control Panel is unable to uninstall Internet Explorer, or if you absolutely have to replace a dead registry and have already tried System.1st or an updated Emergency Repair Disk (ERD).

A no-boot situation may be caused because of a problem with the new shell. To make the shell files compatible with the shell registry settings, boot to safe mode, run Task Manager, press CTRL+ESC, and then type the following:

c:\progra~1\intern~1\setup\ieremove /i:c:\progra~1\intern~1\uninst~1\integr~1.dat

(Do not use the /n: switch.) IERemove will replace only the shell files, and the system will be bootable. Then you can run IE4Setup.exe out of your Internet Explorer 4 Setup folder (if you have one) to solve any problems. You will still need to reinstall programs installed after Internet Explorer was installed.

IERemove attempts to restore the system to the state it was in prior to installing Internet Explorer. This includes restoring the previously used browser. IERemove only replaces core files. It will not uninstall any additional components, even if they rely on the Internet Explorer core to function. Internet Explorer files with no original counterpart stored in the .dat files are not removed. Also, none of the folder structure associated with Internet Explorer will be removed, and Start menu items will remain. If the user had Internet Explorer 3 installed previous to Internet Explorer 4, IERemove will restore Internet Explorer 3 so that it works, although some settings may be lost.

IERemove.exe is found in the C:\Program Files\Internet Explorer\Setup folder. It is a Windows program. When it is run, an uninstall log.txt is created. SetupWbV.dll is not removed by IERemove, so the Advanced Add/Remove dialog box should still be available to users after they are able to boot.

IERemove relies on the backup files and will fail if the backup files are not present. The command-line switches listed below are not required. IERemove looks to the following registry keys for the locations of IE4bak.dat and its corresponding .ini file, and the Integrated Browser.dat and its corresponding .ini file, respectively:

HKEY_LOCAL_MACHINE \SOFTWARE \Microsoft \IE4 \options 

HKEY_LOCAL_MACHINE \SOFTWARE \Microsoft \AdvancedINFSetup \IntegratedBrowser 

If you get an error such as the following when running IERemove.exe, it is likely that the registry keys mentioned above are absent:

Setup could only remove the shell integration option. Internet Explorer 4.0 was not completely removed. 

To resolve this problem, use the command-line switches to specify the locations of the .dat and .ini files. Also, you can force IERemove to remove only the shell or only the core by using only one of the following switches:

• /i:" path \integrated browser.dat" 

• /n:" path \ie4bak.dat" 

Example: 

ieremove /i:"C:\program files\uninstall information\integrated browser nt\integrated browser nt.dat" /n:"C:\windows\ie4bak.dat"

Or, if you don't have long file name support:

C:\progra~1\intern~1\setup\ieremove /i:C:\progra~1\intern~1\uninst~1\integr~1.dat /n:C:\windows\ie4bak.dat

If IERemove runs on a computer that did not have Internet Explorer 3 previously installed, the user may not be able to successfully install Internet Explorer 3 because of version conflicts with Internet Explorer files left on the system. These files need to be renamed.

To find procedures for using IERemove.exe to uninstall Internet Explorer 4 for Windows 95 and Internet Explorer 4 for Windows NT, see Appendix B.