The invalid username error occurs when the Prescreen is installed on two or more windows devices using the same email address. To resolve this error, the Prescreen software must be uninstalled from the devices on which the user does not wish to continue using the software; and must be re-installed (after uninstallation) on the device that the customer wishes to use the Prescreen on.


Steps to uninstall Prescreen from the device:


Step 1: Go to the following file location on the device on which PreScreen is installed:

This PC > Local Disk (C:) > Users > [User] > AppData > Roaming > OneScreen Prescreen


Step 2: Double-click to run the OneScreenPreScreen_stop file (highlighted below):




Step 3: Open the Control Panel on your PC.


Step 4: Under “Programs”, click on “uninstall a program”.



Step 5: Search for “OneScreen Prescreen” (highlighted below) in the list of programs and then click on uninstall/change (marked below).


Step 6: As a confirmation for complete uninstallation, go to the following file location and look for the OneScreen Prescreen folder: 

This PC > Local Disk (C:) > Users > [User] > AppData > Roaming


If the folder is absent, the uninstallation was successful.

However, if the OneScreen Prescreen folder is still present, the uninstallation might not have removed the software completely. To do so, follow the additional instructions below:


Step 1: Anywhere on your PC, press the [ctrl] + [alt] + [del] keys. Open “task manager” from the list of options.


Step 2: In the Task Manager, Open the details tab, find the processes in the image below and right click on each and select “End task”.

Note: Skip any that are not present/running.


Step 3: In the Task Manager, Open the services tab, find the process in the image below and right click on each and select “End task”.

Note: Skip if it is not present/running.




Step 4: After ending all the tasks, return to the Prescreen folder location and delete the folder.


Upon successful completion of all uninstallations, run the OneScreen Prescreen Set-up file on the on the device that you wish to run/use the Prescreen on. You can refer to our installation guide on how to do so.