advice on building the cheapest gaming pc from a compaq

[firebadbobb1]

yeah, as i said, i have a compaq. it has an amd athlon II x3 460. its a socket am3 (938) @ 3.40 ghz. a triple core 64 bit. my ram is 4gig ddr2 dual channel, dram frequency is 401.8 mhz. gpu is an nvidia geforce gt 610. lastly my mobo is a stock pegatron corp NARRA5. the chip-set is MCP61. it isnt great, i know. but what can i upgrade to make fallout 4 run at medium quality? it runs low, and with proper fps mods, it runs tolerable. what can i do to max out this system without buying a new mobo/ or build new system? i do not have the funds to build a new system. i got a baby coming. thank you in advance!!!

 

[Calvin7]

•TDP: 95W
Only socket AM2+ processors are supported with this motherboard. No AM3 CPU.

AMD only made 2 Phenom II X4 CPU's for AM2+, 920 and 940, both were 125 watt TDP which exceeds the boards 95 watt TDP.
AMD Quad Core CPU Phenom X4-9650 2.3GHz Socket AM2+
http://www.ebay.com/itm/AMD-Quad-Core-CPU-Phenom-X4-9650-2-3GHz-Socket-AM2-/182287164264?_trksid=p2141725.m3641.l6368

Looks like you won't make the minimum sys req to run the game.
Minimum

•Windows 7/8/10 (64-bit OS required)
•Intel Core i5-2300 2.8 GHz/AMD Phenom II X4 945 3.0 GHz or equivalent.
•8 GB RAM.
•30 GB free HDD space.
•NVIDIA GTX 550 Ti 2GB/AMD Radeon HD 7870 2GB or equivalent.