My Computer Goes Strait To The PC Screen Only And Duplicate And Doesn't Let Me "add wireless display" And i Checked A Dell Forum And I Did The Thing To See If My Computer Supports Miracast And It Does. So Can Someone Help?

I shall suggest you to turn off Firewall or any anti virus app and recheck the issue.

Hello,

Does the problematic client ever joined domain, a virtual machine or its only a local computer?

Based on my experience, we can first try the following troubleshooting steps:

1. Please be assured that your display and network drivers are up to date.

2. Make sure any virtualization software is not installed on your computer.
    a. Find the wireless network adapter and right click it to select Properties.

    b. On the Networking tab, check see if there are any virtual items.

Thanks,

Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

Hello,

Did the problematic client ever join domain, Is it a virtual machine or its only a local computer?

Based on my experience, we can first try the following troubleshooting steps:

1. Please be assured that your display and network drivers are up to date.

2. Make sure any virtualization software is not installed on your computer.
    a. Find the wireless network adapter and right click it to select Properties.

    b. On the Networking tab, check see if there are any virtual items.

Thanks,

Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

See if http://digitalmediaphile.com/index.php/2015/04/24/trouble-shooting-miracast/ has anything on the list that you have installed or configured.