Install fails with "already installed" or "currently installed" with XCOM for Windows

Products

• XCOM Data Transport
• XCOM Data Transport - Windows

Issue/Introduction

When trying to install XCOM for Windows r11.6 SP02 after a previous XCOM uninstall the following message is displayed
CA XCOM Data Transport is already installed on your system.
It must be uninstalled before the installation can continue.
The installation will now exit.

Older installers may show message as
Install Wizard has detected that an earlier version of
CA XCOM Data Transport for Windows Family Server
is currently installed.
 You must first un-install the prior version before continuing.

Environment

XCOM™ Data Transport® for Windows 11.6

Cause

Some component of the XCOM uninstall process did not complete successfully. e.g. one possible root cause is still having this registry key in existence after XCOM was uninstalled: "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\CA XCOM Data Transport r11.6 SP02 (64-bit)"

Resolution

There is a cleanup utility designed to resolve all problems with incomplete uninstalls for various XCOM versions which prevents a new install from executing.
The utility can be accessed here: Uninstall Program
Note: Per the readme.txt file:
To cleanup 32-Bit versions of XCOM, use cleanup32.zip and file xcomunin32.exe.
To cleanup 64-Bit versions of XCOM, use cleanup64.zip and file xcomuni64.exe.
For Windows Server 2008 SP02, use xcomunin64.exe utility irrespective of XCOM version.

After the relevant xcomunin*.exe file has completed and the server has been restarted the XCOM install should then proceed without any problems.

NOTES:
If the install is still blocked after running the cleanup utility then running the following commands to delete 2 more registry keys may be needed to resolve the problem (has been reported when the previous install was r11 32-bit):
REG DELETE "HKEY_LOCAL_MACHINE\SOFTWARE\ComputerAssociates\XCOM\RemoteSystemsTS\" /f
REG DELETE "HKEY_LOCAL_MACHINE\SOFTWARE\ComputerAssociates\XCOM\" /f  

Additional Information

The latest XCOM for Windows 11.6 service pack SP03 has been enhanced to use similar cleanup techniques to detect any remnants from the previous installation and prompt the user to choose whether to clean those up and proceed with the installation:
XCOM™ Data Transport® for Windows 11.6 Service Packs > Release Notes > New Features- scroll down to see "Service Pack 11.6.03" and "Installation Improvements"

XCOM™ Data Transport® for Windows 12.0 New Features Scroll down to see "Installation Improvements"