From an Administrator-level login, run the Microsoft Management Console --
1. Start, Run, MMC.EXE
2. Click File, Add/Remove Snap-in
3. Click Add...
4. Select: Local Users and Groups, Click Add
5. Click Finish
 
Run Group Policy Edit --
1. Start, Run, GPEDIT.MSC
2. Expand the tree on the left to see
Computer Configuration\Administrative Templates\Windows Components\Windows Installer
3. Double-click "Always install with Elevated Privileges";  choose Enable, OK
4. Double-click "Enable user to use media source while elevated";  choose Enable, OK
5. Expand the tree to see
User Configuration\Administrative Templates\Windows Components\Windows Installer
6. Double-click "Always install with Elevated Privileges";  choose Enable, OK.
7. File, Exit. 
 
Items 3 & 6 add or modify the following registry values:
 
[HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Windows\Installer]
"AlwaysInstallElevated"=dword:00000001
 
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Installer]
"AlwaysInstallElevated"=dword:00000001

Additional notes:

If you install a new program that updates the windows installer, or update the installer components through windows update, the registry keys are re-set to 0 and you have to re-apply the policy changes.

Also, the CD should be in the drive when the user logs on, for best results.  Under the Group Policy edit item #2 above, you may also wish to set the item which determines if local removable media or a network location is searched first for installs;  for larger installation environments, it will be more convenient to place the installation files on a network shared
location so no CD is needed to complete user installs.

Copy the files SHELLWP.DLL, WPFORMAT.DLL, and SHLWP9EN.DLL from the install CD to the %systemroot%\system32 folder.

Copy the text below, and use Notepad to save it to the file WPsummary.REG.  From the Administrator login, double-click the file to incorporate it into the registry.

Start below here ================================
REGEDIT4

[HKEY_CLASSES_ROOT\CLSID\{B95057E0-44DB-11CE-A5D1-00608C83BD3F}]
@="Shell Extensions for WordPerfect"

[HKEY_CLASSES_ROOT\CLSID\{B95057E0-44DB-11CE-A5D1-00608C83BD3F}\InProcServer32]
@="shellwp.dll"
"ThreadingModel"="Apartment"

[HKEY_CLASSES_ROOT\*\shellex\ContextMenuHandlers\{B95057E0-44DB-11CE-A5D1-00608C83BD3F}]
@=""

[HKEY_CLASSES_ROOT\*\shellex\PropertySheetHandlers\{B95057E0-44DB-11CE-A5D1-00608C83BD3F}]
@=""
End above here ================================l=

[Much thanks to Giuseppe Bilotta for initially pinpointing this solution.]

Run REGEDT32 and navigate to HKLM|Software|Corel.  Right-click, choose Security.  Set to Full Control for "Everyone" or for the selected Restricted Users whom you wish to allow to run the program.