Any problems upgrading a Gateway PC?

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1

So I've got a Gateway PC that I wouldn't mind upgrading, but the last one I upgraded had some weird problems happen after I upgraded the PSU and GPU. Anyway, I was wondering if anyone else has had any problems. I was thinking of upgrading my RAM, PSU and GPU. 

 

CPU: AMD A10-5700 3.4GHz

Mobo: Some Acer piece of crap

RAM: 400 MHz piece of crap DDR3, 8GB

GPU: AMD 7670 HD Discrete crap

HDD: 1TB something

 

That's the rig. Should I just scrap it and build a new PC inside the case, or upgrade it? The system name is a DX4380. I was thinking of getting either an HD 7850 or an R7 260X, maybe a 270X. 

Let me know, give me some ideas and feedback, or just tell me "Screw it, get a new PC!" 

2

Screw it, get a new PC!

3

get a bigger psu and this http://www.amazon.com/HIS-Mini-DiplayPort-Express-Graphics-H787Q2G2M/dp/B007HYIRES/ref=sr_1_3?ie=UTF8&qid=1382573404&sr=8-3&keywords=7870

http://www.amazon.com/XFX-ATX-550-Power-Supply/dp/B004RJ8EKI/ref=sr_1_1?ie=UTF8&qid=1382573451&sr=8-1&keywords=xfx+550

4

If you're going to get the ram, psu, and gpu, you'd be better off just getting the rest of the parts needed to build a new pc.