I have two different display dongles, one is a usb-c to hdmi/vga adapter and one is a usb 3.0 to vga external graphics card. I have tried both of these devices on other computers and they work just fine but when I try with me Dell XPS 15 9560 I get the "USB device not recognized" error, I beleive it is error 43. I plugged the usb-c adapter into a Lenovo Yoga 910 and it work immediately without installing any drivers so I don't think it is a driver issue. I have found forums with people updating all of the usb ports in device manager and disable power saving mode and I've tried them all, nothing works. The only common "fix" that I haven't been able to try is changing the wifi power output from 100% to 75% and I haven't done this because my machine has the Killer wifi card which doesn't have this option in device manager. Help please.
What OS are you running? And are you getting this error with both of the adapters or just one? If you get it with both, do you get the error if you try them separately rather than simultaneously? Also, if you're not aware, USB-C to HDMI/VGA adapters work completely differently from USB 3.0 display adapters. USB-C ports have a real DisplayPort output wired to them, which means using display adapters with that port is just the same as if you were connecting the display via a native DisplayPort/HDMI/VGA connector on the laptop itself, although those combo display/USB devices will limit the maximum bandwidth available and therefore the maximum resolution you can run compared to USB-C adapters that only give you HDMI/DisplayPort. By comparison, USB 3.0 adapters do not work this way because those ports (USB-A) do not have a real video output wired to them. Instead, they use what's called a DisplayLink chip, which involves a driver (automatically installed via Windows Update starting with Windows 10 Anniversary Update) that basically uses your CPU and GPU to compress display data for prior to sending it as USB data to that adapter, and then the adapter decompresses it and sends it to the display. This has a few ramifications. First, displays connected through these adapters will sometimes feel sluggish and/or reveal compression artifacts when large portions of the display area are changing at the same time, even when you have USB 3.0 and a fast CPU and GPU. This isn't an issue if you'll be using this display for Web browsing, email, etc, but gaming or full-screen video would not be advisable. And second, battery life will drain noticeably more quickly due to increased CPU and GPU activity.
If the tradeoffs of the USB 3.0 adapter aren't acceptable to you, I would recommend considering either a USB-C dock (or Thunderbolt dock since your system supports it) or else a Thunderbolt to Dual DisplayPort adapter, either of which will keep your displays on "real" display outputs. The Thunderbolt-based options might require updating your BIOS, Thunderbolt software, and Thunderbolt firmware to work properly, fyi. Also note that if you need adapters to convert from DisplayPort to whatever input your displays require, you'll need ACTIVE adapters, not the more common passive adapters.