Once all Citrix applications are uninstalled, verify that the following folders no longer exist on your workstation. Rename any of the folders that you find. To rename a folder, right-click and choose rename, then add ".old" to the end of the folder name.
C:\Program Files (x86)\Citrix
C:\Program Files\Citrix
C:\Users\%username%\AppData\Local\Citrix
C:\Users\%username%\AppData\Local\ICA Client
C:\Users\%username%\AppData\Roaming\Citrix
C:\Users\%username%\AppData\Roaming\ICA Client
The AppData folder is hidden by default. You may need to make hidden folders visible on the PC to gain access to it, or manually enter the path in the address bar in Windows Explorer.