How to upgrade an OEM pc? Lenovo H420, please answer, I need your help!!!

Vindaloovians

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Dec 6, 2013
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I'd like to add more RAM, a PSU, new CPU and a GPU. I'm not sure what cpu my motherboard will take though? Will it have to be 2nd gen? Will 3rd gen work? I really don't want to spend extra on a new windows licence and computer as my guitar recently broke so I need a new one AND a new computer :((( If I need a new motherboard I won't bother and save up longer...

Pc here: (The RAM is actually 1x4GB)

http://www.newegg.com/Product/Product.aspx?Item=N82E16883108632

The parts I will add:

http://uk.pcpartpicker.com/p/3HV5H