Cyrel

You can build a server with any processor, it is a matter of knowing what you want to use the server for and budgeting appropriately. Building a simple file server with an 1800X will just be pissing money away. The lower speed/lower cost processors won't be out until the 2nd half of this year. Not to mention waiting for motherboard prices and availability to improve. When I first built my file server I used an AMD A4-5300 APU that cost $55, it was more than enough to handles 11 drives and various apps like MakeMKV and Handbrake. It was certainly slow at encoding video but since it's a server it doesn't matter, it's not like anyone is trying to use it for anything else while it encodes. This past summer I upgraded it to an A10-7600 to improve Plex transcoding performance. It was an easy upgrade since the motherboard supported the processor and the price of the APU had dropped to $75. AMD have said they plan on the AM4 platform lasting until at least 2020, building any AM4-based system should get you by fine, just wait until you have more options to save money.

Chromebooks are great in the sub-$200 space but with a $400 budget I think Windows machines will be a lot more competitive. As for which one, how about one of these?  
 
https://www.amazon.com/Acer-Aspire-i3-7100U-Windows-E5-575-33BM/dp/B01K1IO3QW/ref=sr_1_3?s=pc&ie=UTF8&qid=1480495325&sr=1-3&keywords=laptop&refinements=p_36%3A-40000
 
https://www.amazon.com/F556UA-AB32-15-6-inch-Full-HD-Laptop-Windows/dp/B01LX0KIGB/ref=sr_1_12?s=pc&ie=UTF8&qid=1480495325&sr=1-12&keywords=laptop&refinements=p_36%3A-40000
 
https://www.amazon.com/HP-Business-Notebook-Quad-Core-Bluetooth/dp/B01GQFBAZG/ref=sr_1_2?s=pc&ie=UTF8&qid=1480495392&sr=1-2&keywords=laptop&refinements=p_36%3A-40000%2Cp_n_feature_five_browse-bin%3A7817224011
 
https://www.amazon.com/Lenovo-Premium-Performance-15-6-Inch-Graphics/dp/B01LGBD0Y4/ref=sr_1_9?s=pc&ie=UTF8&qid=1480495392&sr=1-9&keywords=laptop&refinements=p_36%3A-40000%2Cp_n_feature_five_browse-bin%3A7817224011

much slower DDR4 OC potential on the Tomahawk. No USB Type-c either. or on board DP.

They appear to have very similar power delivery, if this is what you're concerned about, so they should be at least similar in reliability (assuming the boards are reliable).
 
If you're going to be using integrated graphics, you may appreciate the DisplayPort on the ASUS Z170-A. If you're using a graphics card, it's unlikely you'll bother with this port.
 
As for the Tomahawk, you get a second PCI slot (if you're still actually using this), and you have two internal USB 3.1 headers instead of USB 3.0, though no Type-C port, so if you choose to use a device with a Type-C connector, you'll need an adapter, unlike with the ASUS Z170-A.

Default MS Defender, everything I can imagine is up-to-date.

Excellent! I've analyzed your minidump file and found that the following drivers are out of date:
fffff80a`ee580000 fffff80a`ee583a00 GKS16Fltr GKS16Fltr.sys 2011-12-19 (4EEFE432) fffff80a`eaac0000 fffff80a`eaac6000 AsIO AsIO.sys 2012-08-22 (5034AC67) fffff80a`eda60000 fffff80a`edac7000 dump_amdsbs dump_amdsbs.sys 2012-12-11 (50C7A3E8) fffff80a`e9150000 fffff80a`e91b7000 amdsbs amdsbs.sys 2012-12-11 (50C7A3E8) fffff80a`ec110000 fffff80a`ec1e9000 rt640x64 rt640x64.sys 2015-05-05 (5548EDEF) This does not mean there are updates available for all these drivers, however, if you'll read on below...
 
 
ffffce81`e4832908 fffff80a`ec29cb08*** WARNING: Unable to verify timestamp for USBPORT.SYS *** ERROR: Module load completed but symbols could not be loaded for USBPORT.SYS USBPORT+0x1cb08 The crash dump analysis still points to usbohci.sys and USBPORT.sys being the issue, both of which are Windows Drivers. It is extremely unlikely that Windows' own USB Drivers are causing this issue directly, and more likely that a USB device is acting up or has outdated drivers.
 
 
1: kd> lmvm GKS16Fltr Browse full module list start end module name fffff80a`ee580000 fffff80a`ee583a00 GKS16Fltr (deferred) Image path: GKS16Fltr.sys Image name: GKS16Fltr.sys Browse all global symbols functions data Timestamp: Mon Dec 19 17:26:10 2011 (4EEFE432) CheckSum: 0000A5F1 ImageSize: 00003A00 Translations: 0000.04b0 0000.04e4 0409.04b0 0409.04e4 Low and behold, after some research on the Googles, I have found someone else with an old GKS16Fltr.sys driver like you.
http://www.tenforums.com/bsod-crashes-debugging/23333-bsod-driver-less-equal-l1c63x64-3.html#post488823
It appears as though this driver is for a gaming keyboard of sorts.
 
Might I ask what exact model and make of gaming keyboard you have?
Do you have another keyboard you can use to see if indeed it is your keyboard (or keyboard drivers) causing the BSOD?
 
 

More than likely your Blue Screens are being caused by outdated drivers that are incompatible with the Windows Update that was just installed.
I suggest updating your device drivers from your motherboard manufacturer's website to start with.
Think Network / LAN, Sound / Audio, USB Chipset, and Motherboard Chipset.
 
Also, what are you running for security software on your machine?

Could you post your motherboard make and model?
What operating system are you running currently?
And was the update from say Windows 7 to Windows 10? (or 8/8.1 to 10?)
 
Also, please ensure you've configured your startup and recovery settings to create Small Memory Dumps.
http://www.tenforums.com/tutorials/5560-bsod-minidump-configure-create-windows-10-a.html

Alrighty, for giggles, can you update you Audio, LAN, and USB drivers from ASUS website? Just to be sure they're not the cause.
https://www.asus.com/us/Motherboards/M5A97_R20/HelpDesk_Download/

Hey there! Thank you for your help.
 
I think I have solved the problem, I had an Logitech G430 with a USB Soundcard, unfortunately the G430 has broken and I had to set up another mic/earphones duo.
 
I don't like my onboard audio, so I wanted to use the USB Soundcard of Logitech to suspense the white noise, hissing etc. I wondered if it's the one causing issues, I guess I was right.
 
I have unplugged it now, system seems stable for the past few hours.