I did forget  to say in GPO disable sharing files and folders is set to Enabled. But it does not work.

Hi novell1,

Have you looked at the following two guides below. I don't see anything related to just PCoip alone. I know that Client drive can be disabled when installing the agent. Hope it helps.

Use Group Policy to Disable Client Drive Redirection

Use Registry Settings to Configure Client Drive Redirection

i believe you mean Horizon client 4.6 --not View 4.6

also note that ; Configuring the browser on the client system to use a proxy server can cause poor client drive redirection performance if the secure tunnel is enabled on the Connection Server instance. For the best client drive redirection performance, configure the browser not to use a proxy server or automatically detect LAN settings.

Please mark my comment as the Correct Answer if this solution resolved your problem

Navigate to the following path in the GPO:

User Configuration\Administrative Templates\Windows Components\Windows Explorer

Select Prevent access to drives from My Computer. Then check the "restrict all drives" settings and then apply (or force) it to the considered OU.