Made a Build For a Friend, Wondering if it works.

Do you have an SSD?

Made some changes:
PCPartPicker part list: https://ca.pcpartpicker.com/list/jnQQP3
Price breakdown by merchant: https://ca.pcpartpicker.com/list/jnQQP3/by_merchant/

CPU: Intel - Core i5-8400 2.8GHz 6-Core Processor ($227.50 @ Vuugo)
Motherboard: Gigabyte - B360M DS3H Micro ATX LGA1151 Motherboard ($86.99 @ Newegg Canada)
Memory: G.Skill - Aegis 16GB (2 x 8GB) DDR4-3000 Memory ($203.99 @ Newegg Canada)
Storage: Team - L5 LITE 3D 240GB 2.5" Solid State Drive ($72.99 @ Newegg Canada)
Storage: Seagate - Barracuda 2TB 3.5" 7200RPM Internal Hard Drive ($72.75 @ Vuugo)
Video Card: Asus - GeForce GTX 1070 8GB Video Card ($619.99 @ Newegg Canada)
Case: Phanteks - Enthoo Pro M Tempered Glass (Black) ATX Mid Tower Case ($119.99 @ Newegg Canada)
Power Supply: SeaSonic - G 550W 80+ Gold Certified Semi-Modular ATX Power Supply ($90.99 @ PC-Canada)
Optical Drive: LG - WH14NS40 Blu-Ray/DVD/CD Writer ($65.99 @ PC-Canada)
Operating System: Microsoft - Windows 10 Home OEM 64-bit ($117.75 @ Vuugo)
Total: $1678.93
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-05-29 22:42 EDT-0400

- Dropped the CPU cooler. 8400 is good enough.

- Cheaper RAM at the same speed and 16 gigs.

- 1070 GPU.

- Lower wattage PSU of similar quality and good reliability.

- Add an SSD.

Same price roughly.
 
Here is the list:

PCPartPicker part list / Price breakdown by merchant

CPU: Intel - Core i7-8700 3.2GHz 6-Core Processor ($391.50 @ shopRBC)
Motherboard: ASRock - H310M-HDV/M.2 Micro ATX LGA1151 Motherboard ($60.00 @ Vuugo)
Memory: Team - Vulcan 16GB (2 x 8GB) DDR4-2400 Memory ($195.99 @ Newegg Canada)
Storage: Crucial - MX500 250GB M.2-2280 Solid State Drive ($89.76 @ shopRBC)
Storage: Western Digital - Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($49.99 @ Newegg Canada)
Video Card: Gigabyte - GeForce GTX 1080 8GB Mini ITX Video Card ($784.99 @ Newegg Canada)
Case: Corsair - 200R ATX Mid Tower Case ($79.99 @ Amazon Canada)
Power Supply: SeaSonic - S12II 520W 80+ Bronze Certified ATX Power Supply ($59.99 @ Newegg Canada)
Optical Drive: Asus - DRW-24F1ST DVD/CD Writer ($12.30 @ Amazon Canada)
Total: $1724.51
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-05-29 23:20 EDT-0400

This i7-8700 and GTX1080 combo is around 55% more powerful than i5-8400 and RX 580 combo and around 35% more powerful than i5-8400 and GTX1070 combo which is a huge gain. All high quality components.

I left out Windows OS for now as the PC can run without activating Windows. It will function normally without limiting performance in any way. Only few basic functions like Personalization will be missing. Besides that all the Installed software and games will work normally without being limited in any way. You can get him the Windows activation key in future no problem.
 


Why not buy a H310 mobo with i7-8700 and GTX1080 build. There is no reason for not to buy. That H310 board covers all the needs and features you need in a Motherboard without any compromise. Only if you had K series CPU and wanted to OC it then going for H310 board makes no sense. That board comes with all the features and packs in high quality components used in higher level boards. Are you planning to OC i7-8700(that is not gonna work as CPU is locked).
 


Yes he selected Z370 board and a non K series CPU combo which is complete waste of money. He cannot OC that CPU then what good is a board with OC as its main purpose.