Gaming PC $400 (Spare Parts)

[King_CreepaLot]

I am wondering what I could get for $400 to run these demanding games:
. 7 Days to Die
. Arma 3 + 2 (No Dayz)
. Skyrim w/ 2K Textures/WATER/ other mods (No ENB)
. DayZ Standalone
. Those should be the most demanding games I own
* I would like to run Skyrim on Ultra and possibly the other games (But mainly Skyrim)
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. Spare parts I have (Quite outdated but should work)

. A heavily modified DELL Optiplex 745 Case
. Mitsumi Optical Drive x2
. DVD Super Multi Drive DVR-K16TBS
. NETGEAR DS104 Hub
. TRENDnet TEG-PCITXR H/W:3 1R Chipset
. BYTECC BT-PEU310 USB Adapter
. Agere FW323-05A Chipset
. Sabrent SND-P8CH Sound Card
. Cooler Master CM12V CPU Cooler (Missing Parts)
. Verto GeForce GT240 GPU
. Nidec BetaV TA450DC Case Fan (Fairly Damaged)
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I also do not have an OS for this new PC (Would Prefer Windows 7 or 8)
I have a 1440x900 Monitor that works as well as an ergonomic keyboard and mouse, and the rest of the peripherals.

If any of those old parts work, to reduce the price of the PC for an updated CPU or GPU, I would appreciate it. (I don't know much about PC parts, so I don't know how well these work or not)

 

[zallim]

Regarding your old PC I suggest that you keep it for secondary usage as getting new parts along with the old ones will cause undesired compatibility issues and you won't be satisfied with it, so we are going to solve this by building a new PC suitable for your needs and you won't be wasting your money over uncompleted upgrades, however it will exceed your budget limit, the build I am about to share costs 505.47 $ and if you managed to get rebates and promos you will get it for 442.45 $, as you can see in both scenarios it will cost more than 400 $ budget but the results will be impressive.
Sorry mate wish I could have done more but this is the best I can do for now, good luck

PCPartPicker part list: http://pcpartpicker.com/p/fK87NG
Price breakdown by merchant: http://pcpartpicker.com/p/fK87NG/by_merchant/

CPU: Intel Pentium G3258 3.2GHz Dual-Core Processor ($63.99 @ SuperBiiz)
Motherboard: ASRock H97M Anniversary Micro ATX LGA1150 Motherboard ($51.98 @ Newegg)
Memory: Kingston HyperX Fury Black 4GB (1 x 4GB) DDR3-1600 Memory ($22.69 @ SuperBiiz)
Storage: Western Digital Caviar Blue 500GB 3.5" 7200RPM Internal Hard Drive ($35.95 @ Amazon)
Video Card: PNY GeForce GTX 750 Ti 2GB Enthusiast Edition Video Card ($94.99 @ Newegg)
Case: Deepcool TESSERACT SW ATX Mid Tower Case ($42.98 @ Newegg)
Power Supply: EVGA 500W 80+ Bronze Certified ATX Power Supply ($29.99 @ Newegg)
Optical Drive: Lite-On iHAS124-14 DVD/CD Writer ($12.99 @ Newegg)
Operating System: Microsoft Windows 8.1 OEM (64-bit) ($86.89 @ OutletPC)
Total: $442.45
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-09-30 20:27 EDT-0400

 

[King_CreepaLot]

Regarding your old PC I suggest that you keep it for secondary usage as getting new parts along with the old ones will cause undesired compatibility issues and you won't be satisfied with it, so we are going to solve this by building a new PC suitable for your needs and you won't be wasting your money over uncompleted upgrades, however it will exceed your budget limit, the build I am about to share costs 505.47 $ and if you managed to get rebates and promos you will get it for 442.45 $, as you can see in both scenarios it will cost more than 400 $ budget but the results will be impressive.
Sorry mate wish I could have done more but this is the best I can do for now, good luck

PCPartPicker part list: http://pcpartpicker.com/p/fK87NG
Price breakdown by merchant: http://pcpartpicker.com/p/fK87NG/by_merchant/

CPU: Intel Pentium G3258 3.2GHz Dual-Core Processor ($63.99 @ SuperBiiz)
Motherboard: ASRock H97M Anniversary Micro ATX LGA1150 Motherboard ($51.98 @ Newegg)
Memory: Kingston HyperX Fury Black 4GB (1 x 4GB) DDR3-1600 Memory ($22.69 @ SuperBiiz)
Storage: Western Digital Caviar Blue 500GB 3.5" 7200RPM Internal Hard Drive ($35.95 @ Amazon)
Video Card: PNY GeForce GTX 750 Ti 2GB Enthusiast Edition Video Card ($94.99 @ Newegg)
Case: Deepcool TESSERACT SW ATX Mid Tower Case ($42.98 @ Newegg)
Power Supply: EVGA 500W 80+ Bronze Certified ATX Power Supply ($29.99 @ Newegg)
Optical Drive: Lite-On iHAS124-14 DVD/CD Writer ($12.99 @ Newegg)
Operating System: Microsoft Windows 8.1 OEM (64-bit) ($86.89 @ OutletPC)
Total: $442.45
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-09-30 20:27 EDT-0400

Thank you, going to see if I can get any more answers just in case, but I might go for this PC if all else fails.

 

[zallim]

No problem mate and I hope you can get the best deal.