How can I check that the 3CX uninstall completely removed 3CX Phone System?

You can do this using the 3CX Installation Checker Tool.
3CX Installation Checker Utility is a small tool that you can run before installing 3CX Phone System after an Uninstallation.

The tool will provide the information necessary about any previous installation traces of 3CX files that could be still on the system.

There are 5 checks that are done in the checker:

• Checks for 3CX Product Installation
• Checks for existing registry keys
• Checks for 3CX Phone System Folder
• Checks for 3CX services
• Checks for 3CX Assembly Files

Note: The tool will only provide a way to inform the user what’s left on the system. These have to be removed manually for now.

Check 1: Product Installation
Removal Process: Access the registry Start/Run/Regedit and look for the following key
HKEY_CLASSES_ROOT\Installer\Products
Find 3CX Phonesystem and delete the registry key that corresponds to this.

Check 2: Existing registry keys
Removal Process for 32 bit users:
32 bit users: HKEY_LOCAL_MACHINE\SOFTWARE\3CX\Phonesystem – Delete the 3CX Phonesystem key
Removal Process for 64 bit users:
64 bit users: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\3CX\Phonesystem – Delete the 3CX Phonesystem key

Check 3: 3CX Phone System Folder
Removal Process;:
Example: C:\Program Files (x86)\3CX PhoneSystem
Note: This check is made only for installations that are installed on the default path. We will modify this at a later stage.

Check 4: 3CX services
Removal Process:
Access the registry and delete the following keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\3CX PhoneSystem
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\3CX PhoneSystem Database Server
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\3CX PhoneSystem Media Server
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\3CXCfgServ
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\3CXConferenceRoom
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\3CXFAXSrv
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\3CXIvr
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\3CXParkOrbit
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\3CXTunnel
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\3CXVBoxMgr

Check 5: 3CX Assembly files and DLL’s
Removal Process:
HKEY_CLASSES_ROOT\Installer\Assemblies\Global
Search for the following, right click on each and delete:
3cxpscomcpp2
Gizmox WebGui.Common
Gizmox WebGui.Forms
Gizmox.WebGUI.Server
CSharpCode.SharpZipLib
UltiDevCassiniHttpRequestProcessor2.0

Then go to WINDOWS/ASSEMBLY folder and clear the cache.
Right click on each one and uninstall.

It is recommended that the machine is rebooted after the manual cleaning Procedure.

General 3CX Phone System FAQs 

• How to configure secure SIP
• Support procedures
• How can I run 3CX Call Reporter remotely?
• What is the firewall checker and why do I need it?
• How can I use the 3CX Tunnel with a SIP hardphone?
• How do I import the call logs in the database so that I can create Call reports?
• How do I configure a CISCO router for to allow connection to a VOIP provider?
• How to convert a Cisco 7940 from SCCP to SIP
• How do I disable the dual Ring Tone?
• Configuring Exchange Server 2007 Unified messaging with 3CX Phone System
• How do I disable Internet Explorer Enhanced Security Configuration for Windows Server 2008
• 3CX Phone System Support
• What is the cause of Installer error 2738, when installing 3CX?
• How does 3CX Phone System decide whether a call is internal or external?
• Is Microsoft ISA server supported as a firewall?
• How do I configure my Linksys router for 3CX Phone System?
• Why does Media Server report “binding failed”?
• Can hotels with Micros Fidelio use 3CX Phone System?
• How do I install Microsoft Fax services on Windows 2008 for 3CX?
• How do I install Microsoft Fax services on Windows 2003 for 3CX?
• How do I install the Microsoft Windows Vista fax client?
• Why does 3CX require static port mappings (Full Cone NAT)?
• How does Phone provisioning work?
• How do I create a phone provisioning template?
• How can I setup integration between 3CX and Salesforce.com?
• How can I secure phone calls using OpenVPN?
• How can I view SIP traffic with a Network Capture tool?
• How do I configure direct SIP Calls?
• What is a SIP domain and how do I configure it correctly?
• What SIP Phones can I use with 3CX Phone System?
• What phones, gateways and firmware have you tested 3CX Phone System with?
• Analyzing a SIP call
• What VOIP Gateways can I use with 3CX Phone System?
• What VOIP Providers have you tested 3CX Phone System with?
• How do I install the Microsoft Windows XP fax client?