Citrix Online Plugin Uninstall
If you are looking for information how to uninstall Citrix online Plugin you are in right place
Citrix recommends using the Citrix Receiver to install and uninstall the online plug-in. If Citrix Receiver was not used to install the online plug-in, you can uninstall the plug-in by running the Add/Remove Programs utility from the Control Panel on Windows XP or Windows Server 2003 (Programs and Features utility from the Control Panel on Windows Vista, Windows 7, and Windows Server 2008).
If you delete plug-in related files or registry entries just before uninstalling the online plug-in with Add/Remove Programs or Programs and Features, uninstall might fail. The Microsoft Windows Installer (MSI) is trying to repair and uninstall at the same time. If this occurs, use the online plug-in to start an auto-repair. After the auto-repair completes, you can cleanly uninstall the online plug-in from Add/Remove Programs or Programs and Features.
Auto-repair occurs if there is a problem with the online plug-in; however, there is no Add/Remove Programs or Programs and Features Repair option.
To remove the plug-in using the command line
You can also uninstall the plug-in from a command line by typing the appropriate command.
After uninstalling the plug-in software from a user device, the custom plug-in-setting registry keys created by icaclient.adm remain in the Software\Policies\Citrix\ICA Client directory under HKEY_LOCAL_MACHINE and HKEY_LOCAL_USER. If you reinstall the plug-in, these policies might be enforced, possibly causing unexpected behavior. If you want to remove these customizations, delete them manually.
I also recommend to read this article if you have problems with uninstalling XenApp plugin.