Keep Getting Disconnected from wireless internet!!!

I have an Inspiron 17 7779 and it came with an Intel Dual Band Wireless AC 3165.  I replaced mine with a better Intel card.  I replaced it mainly because I did not like the 1x1 configuration and I do not remember for sure if I was having problems with the original card staying connected.

Which Wi-Fi adapter do you have.  Have you checked to make sure your system is running as a Private Network and not Public?  Which card do you have?

Mine also has an Intel Dual Band Wireless AC 3165. I have changed my network to private, however I am still running into same issue

Have you updated the drivers for the WiFi card, preferably directly from Intel's site since they're often newer than that Dell offers?  Have you checked the antenna connections to the card?

If you want to keep that card, any troubleshooting will be up to you.  Things like changing locations to have better access to the router, updating firmware on the router, or testing the system in a different location would be some possibilities.

You could watch the status of the card to see if it were loosing its IP address and to make sure it is using the correct address and not one of the 169.xxx.xxx.xxx addresses.

Signal strength dropping might cause the system to disconnect.  Interference from other devices or even things like wireless phones or microwaves can cause problems.  If you had older wireless devices, they might effect the network.

What I would do is download the latest driver for the system, and I will assume you have the system up to date with all other drivers/bios.  Once the download is done, go offline and uninstall the wireless adapter and check the box to uninstall all drivers.

Reboot the system and install the drivers you downloaded.  Now do testing and I would start with just the Router and system in close proximity to make sure the signal strength is adequate.

If it continues to drop the connection, I would purchase a new adapter and replace the current one.  I feel it is not worth the time or aggravation trying to get something like that replaced.  Hopefully, the driver update will repair your problem.

Older post, but am having same issue with a new Dell laptop.  Set Windows 10 power options for power plan advanced settings for 'Wireless Adapter Settings' --> 'Power Saver Mode' to 'max performance' for both plugged-in and on-battery.  

But then went into Settings from Windows menu.  Checked the wireless adapter properties, clicked Configure button, and looked at 'Power Management' tab.  The checkbox was selected to allow the PC to turn off the network card to save power.  Don't know yet if that's the root cause.  And ideally the updated power management settings wouldn't cause the card to be turned off.

Intermittent or transient issues can be tough to troubleshoot.  If it's related to Win 10 power plan, checking these two items is worth a shot.  And it doesn't require opening up your laptop.