XPS 420 Upgrades to PSU and GPU

[Bolillo]

Okay a friend of mine has an xps 420 that he gave me so that i could give it a refresher and upgrade it to windows 7, he asked me if it could be upgraded a bit more than how it is right now because he doesnt want to build a pc right now but he just wants to play some games that look good on this pc.
Specs are:
CPU: Intel Core 2 Quad Q6600 2.4GHz
RAM: 4GB DDR2 @ 332mhz
Motherboard: Dell 0TP406
GPU: Nvidia GeForce GTS 450 1GB GDDR5
PSU: Stock Dell 375w
What can be upgraded here?
Also i have read other threads but none are really from 2014 so maybe there is newer stuff that can be used here.

 

[rolandzhang3]

Well a GTX 750/Ti should work with that system without a PSU upgrade (I wouldn't recommend any GPU higher up for a stock Q6600 based system).

From what I've seen online the XPS 420 uses a BTX motherboard which would usually be a bit problematic with clearance issues, though in an XPS 420 there is usually enough clearance room to fit a dual slot GPU, it'd still be a good idea to get a single bracket card though.