Geoff Chappell - Software Analyst
That software can be installed and uninstalled, over and over, often with no apparent harm, seems miraculous to me. Indeed, I don’t believe it. The exercise is straightforward enough when a program installs its own files and registry entries, etc, that are no other software’s business. Where things get complicated, possibly without a well-defined solution, is with resources that are potentially of interest to multiple programs.
Uninstalling Microsoft FrontPage 2002 from Windows Vista deletes registry keys for the following file types:
With these file types unregistered, you may notice odd behaviour in any number of programs. Perhaps most readily noticed will be that the Windows Explorer and the common dialogs for browsing files and folders will show the plain file icon for GIF, JPG and PNG files instead of the more helpful , and . Another example is that pictures are missing in Windows Help and Support.
When installing, FrontPage sets its own values in the registry keys associated with each of these file types. When uninstalling, FrontPage deletes each key, apparently not aware or not caring that the key existed before FrontPage’s installation or may have been modified by other software since. It’s hard to escape the notion that FrontPage’s programmers thought to treat these file types as FrontPage’s own to configure however FrontPage wants. This is at least a little odd, on top of being presumptuous, given that each of these file types has at least some registry entries even in a clean Windows installation, in all versions from at least Windows 2000.
Incidentally, installing and uninstalling FrontPage exposes two other types of potential error. First, registry keys for the following file types are deleted when installing FrontPage but are not restored when uninstalling:
Second, installing FrontPage adds registry keys for the following file types, which remain after uninstalling:
As if to prove that none of this got much thought, the left-over registry entries for these types are only partly valid: each has a DefaultIcon subkey that names a DLL as providing the default icon for the file type, but the uninstaller has deleted the DLL.
Unfortunately, no simple solution exists that is certain for all cases. If the registry keys for a file type are gone completely, then at least some solution is obtained by restoring the keys as if Windows were freshly installed. Of course, this can do nothing for registry entries that were added by other programs.
The following table provides links to Registration Entries (REG) files that arrange a clean refresh for each file type and show which registry keys are affected. Before downloading any of these settings files, much less attempting to use them, start the Registry Editor, browse for the applicable keys and verify their absence. Otherwise, the effect of restoring their initial settings depends on what is now in the keys and is not generally predictable.
If you are concerned for the security implications of downloading a file that may change your computer’s configuration, and I suggest strongly that you should be, then save the settings file instead of opening it, and inspect it using Notepad to check that all it does is specify entries for the applicable keys. Note anyway that you need administrative privilege to install these registry settings.
|Clean Registration Entries for the ASP File Type||HKEY_CLASSES_ROOT\.asp
|Clean Registration Entries for the GIF File Type||HKEY_CLASSES_ROOT\.gif
|Clean Registration Entries for the HTX File Type||HKEY_CLASSES_ROOT\.htx|
|Clean Registration Entries for the JPG File Type||HKEY_CLASSES_ROOT\.jpg
|Clean Registration Entries for the PNG File Type||HKEY_CLASSES_ROOT\.png
All these REG files are prepared for Windows Vista. Clean settings for earlier Windows versions would differ, e.g., for the location of each file type’s default icon, but the differences are beyond my interest for this note.
The REG file for GIF files sets Internet Explorer as the default program for opening GIF files. If your Internet Explorer is not installed in “C:\Program Files\Internet Explorer”, you will have to edit either the REG file before using it or the default value of HKEY_CLASSES_ROOT\giffile\shell\Open\command afterwards.
If you want to refresh the keys for all the file types, then use Clean Registration Entries for File Types Uninstalled by FrontPage 2002 (which is all the table’s REG files rolled into one).
Note that Windows programs will typically not use the new settings immediately. You may see mixed effects, possibly until your next logon.