@adrialanta  if you haven't already, try getting the latest version of the DisplayLink software directly from DisplayLink.com in case something like a recent Windows update may have broken the currently installed drivers somehow.

Yes, I had already made sure I had the latest software updates.  Miraculously it started working properly again until now!  The laptop is no longer being detected as a monitor display and the screen is black.  The external monitor is the only active monitor display, so the reverse of my original problem is now happening. 

If I unplug the laptop from the docking station, the laptop monitor display works just fine.  It seems it may be a problem with the docking station?  Is there a way to test and confirm the problem is with the docking station before I purchase a new docking station?

Thanks

@adrialantathe most straightforward way to test the docking station would be to try it with another system, which would involve installing the DisplayLink software on that other system.  That software is available for Windows, macOS, and Linux, so you've got options if you happen to have access to another system at all.  But honestly I don't think a dock problem would explain your built-in display going black when the dock is attached.  I would recommend doing the following:

- Disconnect the dock
- Uninstall DisplayLink software
- Reinstall your system's regular graphics drivers, even if you'd be reinstalling the same version you're already running
- Reinstall DisplayLink software
- Reconnect the dock

The reason I suggest all of that is that especially given that you mentioned that this used to work, I think it's more likely that a recent Windows update or possibly a graphics driver update may have introduced this problem.  Windows updates and driver updates can both be delivered automatically in the background, so that seems more likely to account for this behavior than a dock problem.  I'm also hoping that just reinstalling the latest version of everything in order will resolve whatever may have become broken, as opposed to this behavior being related to a bug that was newly introduced in some update and would therefore require removing/downgrading that update.  That would be more effort to identify root cause, but there have certainly been cases like that.  I remember back in January 2020, Intel released a new graphics driver package that broke 5120x1440 resolution, so people using those displays who received that update were suddenly limited to a lower resolution.  The only real fix at the time was to roll back to the previous driver version.  That may have been fixed by now, but I mention it just to illustrate that this type of stuff does happen, and automatic background updating means that things can suddenly be broken one day even without you actively doing something.

Thank you for responding!  When I disconnect my laptop from the dock, the internal monitor returns to a normal display, when connected to the dock it is not detected.  So, when you say "reinstall the system's regular graphics drivers" does that mean reinstall the drivers for the external 2214H monitor, because those are the only drivers I have on a disk.

Thanks

@adrialanta  Happy to try to help.  When I said reinstall your graphics drivers, I meant the drivers for the actual graphics controller chip in your system.  I wouldn't rely on a disk for any drivers, since they would likely be outdated for now.  You can find drivers for your system at support.dell.com.  Enter your Service Tag or exact model name (Inspiron 17 is a generic term for a 17" Inspiron system, of which there are many), and then go to the Drivers & Downloads section.  Depending on the system model, the graphics drivers would be for an Intel, NVIDIA, or AMD graphics chipset.

Hi...I hooked up my HP laptop also running on Windows 10 and did not install any Display Link software and it worked just fine, using the Laptop monitor and the external monitor as an extended display.  So now I know it is not the 3100 dock.  I also tried to download some driver updates on the official Dell support website but downloads would not complete...made it to 50% yesterday and just hung up and this lasted for 2 hours so I canceled it...tried again today and never went past 0% for more than an hour so I canceled it.  These are the drivers that were to be installed after my system was analyzed:

Dell Inspiron 7746 System BIOS 7746A10.EXE (4 MB)
Intel Dynamic Platform and Thermal Framework Driver 7746_Chipset_Driver_P4RW9_WN32_8.1.10600.147_A00.EXE (31 MB)
Intel Chipset Driver 7746_Chipset_Driver_FHH52_WN32_10.1.1.7_A00.EXE (15 MB)
Intel Rapid Storage Technology Driver 7746_Serial-ATA_Driver_NMD0D_WN32_14.5.0.1081_A00.EXE (41 MB)

However, when I unplug my Dell Laptop from the 3100 dock it works fine with just the internal monitor and when hooked up to the 3100 dock it will only display on the external monitor and laptop monitor goes black.

I am now at a total loss on what is going on...any suggestions??

@adrialanta  basic DisplayLink drivers have been provided via Windows Update for a while now, so if you connect a DisplayLink-based dock or simple dongle to a system that doesn't have DisplayLink software installed, Windows will default to searching Windows Update for a suitable driver -- and Windows Update will provide one.  This will make it appear that things "just work", but in reality Windows just automatically downloaded a driver that it didn't already have.

As for what to do next, none of the drivers in your list are your graphics drivers, although the BIOS update name finally indicated what specific Inspiron 17 model you have, which you hadn't specified earlier.  So if you want to attempt the suggestion I made earlier, you can download (but do not yet install) your system's graphics driver here, and then download (but do not yet install) the latest DisplayLink drivers from DisplayLink.com.  Then disconnect the dock, go to Programs and Features within Windows, and uninstall any DisplayLink item you find.  Then uninstall the Intel HD Graphics driver item.  Then restart your system.  Your display might look different after this, which is fine.  Then install the graphics driver that you previously downloaded from that link above.  Restart your system.  Then install the DisplayLink software that you also previously downloaded.  Then try connecting the dock again.

The other updates that Dell Support offered wouldn't be a bad idea either.  But you might have more luck getting "normal" updates later if you simply install Dell Update onto your system rather than using the mechanism in the Dell Support page.  You can download Dell Update here.  Then just launch it and have it check for updates.  But that won't help when the goal is to reinstall existing software as I'm trying to suggest above. That's meant for updating outdated software.

I can't really help you with stalled downloads.  Hopefully that was just a temporary hiccup somewhere.

Hello, I did not follow the steps to reinstall the graphics drivers because I had not read your post yet... but I did delete the display link drivers and disconnected from the dock, then downloaded the latest Display Link drivers from their website the reconnected the dock and now everything is working just fine. 

I will now download the Dell update and attempt to do my other system updates from that.  Since I purchased this laptop from Dell back in 2015 I had the hard drive replaced, so maybe that is why trying to update from the Dell support website does not work because it was not installed by Dell??  (just guessing)  

However ...THANK YOU VERY MUCH FOR YOUR HELP!!