I've been having this problem since June... reset my computer back then and It seemed to fix it for the time being, but it came back three weeks ago, this time a reset didn't work.
Back in June it first started out with small freezes that increased in frequency, then eventually to severe freezes here and there. It just seems to be getting worse and worse, now playing on singleplayer BF4 even I'll get a 1 second hard freeze every 5 minutes. 
I can only describe the freeze as if you are playing a video and it freezes completely for a second or lags EXTREMELY (Like from 100-20 FPS) for one second and then continues on playing like nothing happened.
Ill get a solid 90-110 FPS on Ultra or more... in every single one of my games. 
I've downloaded MSI afterburner and I've been running the monitoring graphs while I game, It seems when the severe freezes happen my Graphics Card (GPU) Usage will drop from 100 to zero. The Power % will drop down about 50% and the CPU usage will drop down slightly. (Im assuming the Power usage and CPU usage dropping is because of the graphics card going down to zero)
(Pictures are attached)
Even sometimes just running system processes like the search bar, it sometimes will lag a bit.



My Specs are not bad... This computer was built back in October of last year, so since the problems started back in June, it started when the computer was less than a year old... I don't do hardcore stuff, Just casual gaming, surfing the web, facebook, watch TV, do work. I don't go overclocking my computer, I don't play videogames every single day for 8 hours. In fact I don't game every day. This thing ran fine before June.
-i5 6600K 
-Zotac GTX 970
-AS Rock H170M Pro 4
-16GB Gskill ram (4x4GB) @ 2133mHz
-Corsair H55 Liquid cooling
-Mushkin 240GB SSD (Games installed on SSD)
-Seagate Barracuda 1TB HDD
-Rosewill 700W PSU
-Windows 10 home
-1080P main monitor
-900x1440P aux monitor

I didn't run any fan adjusting software until June, but my CPU temps were about 55C on load and GPU temps were 80-81 on load without fan adjustment. Now with fan adjustment (Just GPU) (Ive really paid attention now) CPU is about 22-25C idle, 50-55C on load, GPU is about 23-30C on idle and 70-73C on load. 

Things i've tried:
-Tried a bunch of different drivers, 362, 368.22, 347.25, 344.11, 372.(something), 367.(something), and I think something else, I haven't written all of them down.
-checked Dram frequency to make sure its running at the proper frequency
-Made sure all the cores were unparked 
-Used "Driver Booster 4" to update drivers
-Cleared temp files and checked for virus/ malware
-Turned computer and graphics card on performance mode
-Tried capping in game FPS at 60, 70, 80, 85, 90, 100
-Tried using Vsync
-Turned maxiumum pre-rendered frames to 3 (Nvidia support suggested)
-Tried turning 4x MSAA to 2x MSAA
-"Refreshed" Operating system twice
-used sfc/scannow multiple times
-Turned off origin in game
-Ran windows memory test
-Ran Lu dashi, (A Chinese hardware stress testing software my dad suggested, everything came out to be essentially excellent, said my SDD was average though)
-Checked SMART data for SSD (Im at 80% health...)

It seems even at a lower FPS or even on the lowest settings this will still happen. It shouldn't be happening even on the highest settings, it ran fine before problems started happening in June. I could run Battlefield 4 on Ultra, listen to music and have a bunch of Chrome windows open, whilst having my chrome window open on my second screen talking to people on facebook. 

Im... really stumped. Im looking online and it seems that Im not the only one with this kind of a problem, lots of people have problems with Nvidia graphics cards that are either the same as my problem or very similar. Especially with the GTX 970 apparently. 
If I could get some help I would really appreciate it!

Thank you!

Sorry for the late reply, I just got home from classes.

Thanks Sajin! Ill try #1 and #2 and see what happens. Im assuming with the clean boot, I would boot up and try to play the game and see if it gives me problems?

Andrew, Ill do that once I finish with Sajin's suggestion of a clean boot and a clean install of drivers

Thanks! ill be right back

EVGATech_AndrewA
I do apologize for the inconvenience you are having with this issue. Can you run a benchmark using 3DMark Firestrike then post the link with the results in here?

I'm really confused about 3DMark Firestrike right now...
I need to download 3DMark via steam then add the firestrike add on? And 3Dmark is $30?

I suppose Ill download the demo for now and ill let you know with the results!

Yeah... I suppose I may need to try a clean install.

Im almost through the demo, Ill run the demo version of firestrike first then ill go download the other one if needed.

Yep, score looks good, fortunately :)

What should I try next?

Thanks Sajin.
Sorry for the late reply, ill do a clean install over the weekend.

How should I make sure all my system drivers are up to date? I've never done a clean install before. Doing a clean install, it wont automatically update me to the newest windows 10 build right? i'll have to run the windows update service to update all my windows drivers right?

I have the disk for my graphics card and my motherboard, when do I plug those in to make sure the system starts up right?

Thanks

I probably should've been more clear.
First time I did a reset or refresh. through Windows. Which reinstalled the OS but then kept my documents and pictures (not applications)

Second time I did it, it was a reset.
I used "reset this PC and don't keep any files"
Which to my knowledge is the same as a clean install, as it formats the disks and reinstalls the OS without keeping anything but the OS.

Still worth doing a fresh install...?

Wooohah
Still worth doing a fresh install...?

Yes.

Wooohah
Alright, Thanks! I'll create the installation media tomorrow when I get home and I'll do the fresh install soon.

For my motherboard, what drivers do I need? Just bios?
And I don't need any drivers for my SSD or HDD right?

You could update your motherboard bios to the latest version if it isn't fully up to date. All the drivers listed are all you need.

Wooohah
Perfect, thank you.
So apart from that all I need to update is bios

No problem. Yes, that is correct.

Report back once you get everything reinstalled & tested. 

candle_86
What are your temps right before the freeze, this sounds more like the card resetting itself due to thermal issues

With MSI afterburner fan control on, about 70-73 deg.
Without any fan control it used to be 80.

http://www.howtogeek.com/224342/how-to-clean-install-windows-10/amp/

Just download and install the drivers after windows is installed.

No problem. Let me know how it goes.