G3 17 3779 Windows 10 freezing very often

Its not Dell actually, its Intel processor that is suffering from C-State bug, there are millions of computers out there with Skylake processors. https://www.pcworld.com/article/3021023/hardware/how-to-test-your-pc-for-the-skylake-bug.html

Yah, same here. I don't know if it's the Skylake bug or what but mine freezes once and a while. It happened when I first got the computer a few times. I spoke with tech and they said it was from Windows updates. It didn't happen again until a couple days ago. Mine seems to freeze when I'm steaming. It's not exactly "complex" or processor demanding but maybe it is the bug and updates. I'm not sure what it is but it "feels" more like Windows than the computer, if that makes sense. 

Exactly the same symptoms. Freezes randomly, screen on but no mouse pointer or other activity. Sometimes it froze while I was using it (mostly browsing) and others it was just sitting on its' own idling or downloading in the background and I just found it frozen. Intervals and occasions seem completely random. A quick and dirty fix is to remove and then reinsert power supply cable. This restores computer to completely normal operation. But it's extremely annoying and eventually the power supply socket will wear out. Hope Dell can figure this out.

I disagree.
It can freeze while its idling. CPU is doing zero operations.

I have this exact model and have it working fine.  Let me share what I've gleaned from several forums over the past few months, what I've tried, and what is working for me now.

Write down what you are changing in case you need to undo your settings and restore to defaults.  I didn't break your machine by offering these suggestions - I'm simply offering some alternatives because, like you, I was desperate. 

Make sure you have all your BIOS and driver updates before starting.

1.  THIS REALLY HELPED:  Change from a Bluetooth to a corded mouse.  Actually sped up my machine too.

2.  Disable C-States in BIOS (I think it's under the 'Performance' tab when you enter BIOS - just look around. There is a checkbox that you un-check, then save and reboot).

3.  Disable/Spoof "Turbo Boost" into not activating:  https://superuser.com/questions/627665/how-to-disable-intel-turbo-boost-on-my-dell-laptop-with-i5-processor

4.  Try setting Windows 10 Power Management to these values:

Cortana search box > Search on Power & Sleep Settings > (Related Settings) Additional Power Settings > (See Dell Power Plan activated) Change Plan Settings >  Change Advanced Power Settings > Power Options window:

a.  Turn off Hard Disk After:  Set all to "10,000" minutes

b.  Internet Explorer, JavaScript settings:  Set all to "Maximum Performance"

c.  Desktop background settings:  No changes

d.  Wireless Adapter Settings:  Set all to "Maximum Performance"

e.  Sleep:  Set all to "Never, Off, or Disable"  accordingly.  This means you may have to manually put your PC into sleep mode using the Win 10 menu and exit sleep using the on/off button on your laptop.  No big deal.

f.   USB Settings:  Set all to "Disabled"

g.  Intel Graphics Settings:  Set all to "Maximum Performance"

h.  Power Buttons & Lid:  No changes, or set the way you like

i.  PCI Express:  Set all to "Off"

j.  Processor Power Management:

      -  Minimum Processor State:  Set all to 15%

      -  System Cooling Policy:  Set all to "Active"

      -  Maximum Processor State:  Set all to 85%

k.  Display:  Set to your liking

l.   Multimedia

      -  When Sharing Media:  Set all to 'Prevent Idling to Sleep"

      -  Set all others to your liking

m.  Battery:  Set all to your liking

Select "OK" button when done to save your changes

5.  Disable the NVIDIA Drivers that may be conflicting with the Intel Video Drivers

Cortana search box > Search on Device Manager > Display Adapters > (right click) NVIDIA GeForce entry >  Properties > Disable Device (save settings by selecting "OK").  Don't delete the device, just disable it.  Your monitor resolution may change to 480 X 600 or something like that, just change it back to the Hi-Res settings you are using now using the normal method (right-click on desktop, etc., etc,)

6.  Activate more CPU cores:  https://answers.microsoft.com/en-us/windows/forum/windows_10-performance/how-to-activated-all-the-processors/c3fcc1fe-1f44-4dc1-a8f6-676266454fc0

I set my number of processors to: 12.  You may not have to go that high.  I think 1 is the default.

That's it.  My Top 3 suggestions:  Disable NVIDIA drivers, use a corded mouse, disable C States in BIOS.

How I use my Dell:  Not a gamer; used for graphics (Illustrator, Photoshop) and business.

Good luck!  If all else fails, the unplug/replug power cord method always worked for me before I made all these changes.

Your suggestions could not help me either, the problem persists despite the Samsung 860 evo SSD. Too bad!