17 R3, Thunderbolt connection

If you get a popup, chances are that Thunderbolt is already set up. Maybe the message refers to the fact that the dock can’t charge your system since it requires more power than can be carried over Thunderbolt? But if all you want is an extra HDMI output, a dock is way overkill. Just get a USB-C to HDMI 2.0 cable or dongle. They’re inexpensive and much less to deal with. Or you could run both displays off that port using a USB-C to dual HDMI adapter, or a Thunderbolt 3 to Dual HDMI adapter. The difference between those two is how much bandwidth you’ll have available. You might need a Thunderbolt version depending on the resolutions of the displays you’re running.

But if you want to verify your system’s Thunderbolt setup, make sure you’ve installed the latest version of all of the following: System BIOS/firmware, Thunderbolt drivers/software, system Thunderbolt 3 controller firmware.

@Denise Belair  in addition to my post above, I was going to post direct links to the updates I mentioned to help you find them since you mentioned you weren't tech-savvy, but I just noticed that you say you have an "Alienware R3".  The R3 means "Release 3", i.e. the third generation of a given product, but it's not clear which Alienware product you have.  The full model name would be something like "Alienware 15 R3" or "Alienware M17x R3".  If you have that, I should be able to find direct links to the updates I mentioned.  If you don't have that, go to support.dell.com and enter your service tag and the site will identify your model.  Do NOT post your Service Tag here though.

Thankyou for your reply.  oops sorry. I have Alienware 17 R3. 

Yes I know the Caldigit Mini Port is probably overkill but why wont it work? 

We do have all the latest updates from DELL website with specific to my machine. 

The Caldigit mini port is powers itself off the laptop. I am not looking to power the Caldigit miniport. My laptop basically sits still and used as a desktop. I have one 4k monitor running off the actual HDMI port on my Alienware 17R3 (which has only one). I tried using a splitter HDMI on the one HDMI port and all it does is makes both monitors look the same as "monitor 2". ie just copies of each other. Yes I could use a USB-c to HDMI adapter from the Thunderbolt/USB-c port BUT I have this thunderbolt port why not use it? As stated it does not seem to be the Caldigit minport itself as it works on another newer DELL my husband has. There seems to be an issue with my laptop software somewhere that it wont accept the Thunderbolt port. 

Also I just found out I can ask for PRosupport via my warranty. I might try there too. 

@Denise Belair  I'm going to guess you mean the CalDigit Mini Dock since I can't find anything called a Mini Port on their website.  In terms of why it won't work, since you've already confirmed that it works with another system, my best guess is that it's because the most recent Thunderbolt firmware update offered for the Alienware 17 R3 as of this writing, here, is from November 2016 and updates the firmware to release NVM21.  That's very old -- my Latitude 7480's Thunderbolt firmware is NVM40, for comparison -- and systems with older Thunderbolt firmware releases are known to have problems with certain peripherals.  For example, the XPS 15 9550 for a long time couldn't use Thunderbolt 3 to Dual DisplayPort adapters because the newest firmware Dell offered for it (NVM16) was older than the one Intel said was necessary to use such adapters (NVM18), and Dell took quite a long time to release newer firmware to bring it more current -- even though they had up-to-date firmware available for the newer XPS 15 9560 that used the same Thunderbolt chipset (but the 9560's update utility still didn't work for the 9550).  So despite Thunderbolt 3 being a standard, it can still be an interoperability minefield.

An HDMI splitter only ever provides a mirror signal because HDMI sources do not support running multiple independent displays from a single output.  Only DisplayPort does, and by extension USB-C/TB3 because they use DisplayPort protocol to carry video data.

But unless you go into your BIOS and find that your system's Thunderbolt 3 capability has been completely disabled such that its USB-C/TB3 port operates only as a USB-C port -- which is possible to do on at least some systems -- then I don't think this is a case of you needing to enable anything.  You can and certainly should check those BIOS settings, but if that doesn't work, and you've already verified that the Mini Dock works elsewhere AND that you're running the latest available firmware and drivers fro that system, then outdated firmware is likely your culprit.  As a data point, ask your husband to check the Thunderbolt firmware version of the newer system where he got the Mini Dock working.  He can do that by launching the Thunderbolt Software, right-clicking its system tray icon, clicking About, and checking the "NVM Firmware version" field.

Thankyou so much for your very detailed reply. 

I think you are probably right the firmware for the thunderbolt is outdated. 

I will get hubby to check his version. 

After all the hassle, the Caldigit MiniDock is going back or will be repurposed elsewhere (ie hubby will take it   ). 

I got my system working with a very simple USB-C to HDMI adapter. Yes I should have done that in the first place. Lesson learned. But there also should be more recent updates available. 

Basically my Thunderbolt port is useless. Good thing I am not a gamer... 

Thankyou so much for your help though. 

Followup from Hubby: 

I just had a look at this. 

@Denise Belair  even NVM23 is very old for an XPS 13 9370.  Dell has an NVM40 firmware update for that system here, in case he wants to update.  He might need to update his system BIOS/firmware and Thunderbolt software first before that Thunderbolt firmware will be accepted though.