Assuming this is a terminal server...
Group Policy Management Console > Computer Settings > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > "Do not delete temp folder upon exit"
"If the status is set to Enabled, users' per-session temporary folders are retained when the user logs off from a session.
"If the status is set to Disabled, temporary folders are deleted when a user logs off, even if the administrator specifies otherwise in the Remote Desktop Session Host Configuration tool.
"If the status is set to Not Configured, Remote Desktop Services deletes the temporary folders from the remote computer at logoff, unless specified otherwise by the server administrator."