Did you reset it to factory defaults?
I'm thinking about getting this to replace my WRT150N. Looks like it would fit your requirements as well.
http://www.newegg.com/Product/Product.aspx?Item=N82E16833320023
Consider an Asus laptop. This one has a plenty of power and a discrete graphics card (Photoshop can use a graphics card for rendering which increases speed).
N53JF-XE1
The GPU-Z version you have on your list is very outdated, it's on version 5.3 now. If you link to the root of our GPU-Z download directory it will show the latest version by default and give you the choice of downloading older versions if need be...
You can't overclock your Dell. The BIOS and/or motherboard just doesn't have that feature. No you're not going to be able to find an unlocked BIOS either. I can probably count on one hand the number of times I've heard of someone successfully overclocking their dell and that was on older...
You said it shut down, but you didn't specify whether it turns back on. Is this random power failure or is your computer completely dead? The link below will show you how to test your power supply.
How to Manually Test a Power Supply