Installation cleanups get easier

Remember the good old days when all you needed to do to uninstall an application was delete its directory and remove the directory from the PATH command? Nowadays, application installers don't just create directories and files; they modify the Registry, profiles, and who knows what else.

These invasive installations leave administrators asking, "What exactly did this program do when it installed?" More important, administrators wonder, "What must I do to completely uninstall the application?"

Sure, many programs come with uninstallation programs, but these uninstallers are of limited value. They usually don't remove Registry settings, and they often leave directories and files behind. Windows NT administrators need a set of utilities that can spy on a setup program, note every change the program makes, and use that information to undo the installation.

The INSTMON Trio
Microsoft Windows NT Server 4.0 Resource Kit, Supplement Two comes with a trio of utilities--INSTALER, SHOWINST, and UNDOINST--that work together to completely remove applications from NT. After you install the resource kit, you find the uninstallation utilities in the INSTMON subdirectory of the directory you installed the resource kit utilities in.

INSTALER is the trio's spy. Instead of directly running a setup program, you tell INSTALER to run the setup when you want to monitor an application's installation. INSTALER records everything the setup program does, including obscure operations such as making API calls and debugging output. INSTALER records the setup program's changes to your system in a non-ASCII file with the extension .iml. The utility saves the .iml file in the INSTMON directory.

SHOWINST is the tattler. It reads the .iml file that INSTALER creates and reports to you the information that INSTALER records.

UNDOINST is the fixer. It uses the information from the .iml file to ruthlessly zap files, directories, and Registry entries.

When UNDOINST completes, the application is gone, and your system contains almost no trace of it. (The only trace of files that UNDOINST has trouble removing is applications' listing on your Programs menu. Hey, no utility's perfect.)

Putting the Trio to the Test
To try the INSTMON utilities, install a 32-bit program such as winzip95.exe, which you can download from SHAREWARE.COM (http://www.shareware.com). WinZip 6.3 is a good 32-bit file compression and uncompression routine, and winzip95.exe is WinZip's setup routine.

To use INSTALER to install WinZip, type

instaler wzip winzip95.exe

at a command prompt. (Wzip is the filename I selected for the .iml and log files INSTALER creates during the WinZip installation.) INSTALER displays hundreds of lines of information about what winzip95.exe is doing. You can safely ignore this information as it scrolls by, but if you'd like to look at the information in detail after the installation completes, open the wzip.log file. (You don't need wzip.log to uninstall WinZip.)

After you enter the instaler command, winzip95.exe runs, installing WinZip. After WinZip installs, INSTALER terminates, telling you it created a file called wzip.iml.

If you want to find out the names of the files winzip95.exe created and see what other changes the WinZip installation made, type

showinst wzip >report.txt

at a command prompt. This command will generate a text file, report.txt, that summarizes all the file, directory, Registry, and .ini file changes that winzip95.exe made to your system.

If you want to wipe WinZip off your computer altogether, use the application terminator, UNDOINST. Open a command prompt and type

undoinst wzip

In my tests, UNDOINST removed all traces of WinZip except for its presence on my Programs menu. I still see a WinZip entry when I click Start, Programs, even though the application is no longer on my machine. The INSTMON programs don't offer the functionality of Zero Administration for Windows (ZAW), but they're pretty neat!