That's what we already did when we talked about the interface on the motherboard. If you're talking about the power connections, it seems that both his old power supply and his new power supply will have both SATA and Molex connectors. That's why Jenny said you might want to see how many connections of each you will need.

The SATA and Molex connectors on the power supply are for the hard drive(s) and/or DVD drive(s). For example, if he had two hard drives and one DVD drive and they were all SATA, he'd require 3 SATA connectors. The power supply you picked out had 2 SATA and 4 Molex. Though there are adapters to change SATA to Molex and vice versa, I don't see that the power supply you picked out included any. ***Here*** is a picture of the adapter. Considering the age of the E521, it might have all SATA connectors. The hard drives are certainly SATA according to the manual but I'm not sure about the DVD drive.

If he got a more powerful card than the HD 5450, he might need a separate connector for that. But none of the HD 5450's I looked at required one.

ok, looks like he is using 3 sata connectors... now gotta find a PS that has 3 sata's that will fit..how's this


450

Is it difficult to put an extra fan in? I found a nice article on youtube for fans

That one looks OK.
Adding an extra fan is not difficult as long as the computer case has a good place for one.

this is a terrible pic but this is his connections

connection

Thank you two very very very much!!!!! I have given Tommy all he needs to decide if he wants to upgrade his computer... if you like I will let you know what he does and if he is successful ... :-)
Thanks again could not have answered his questions without you two... I am not hardware smart at all!!!

That Antec power supply is a really good option. It has everything you could possible need including special connections for a video card that might need them. I can't make anything out on that pic. The computer case will need to have a place for an extra fan... if it doesn't, you are stuck with what you have.

Is this really all worth it? For $542 he could get a low-end computer from eCollegePC that will run super fast compared to this one and do what he needs it to do and still have options for upgrades without all this trouble trying to make something old work with new hardware. For an extra $49, he could put in an Nvidia GT 720.

I passed this along to him... I looked at this...edit.... doesn't list a fan so he would have to add one I take it

It's a SATA connector, but I can't make out if it's the power or the data connector.

Here's a YouTube where someone installed a Corsair CX500 power supply in a Dell E521
https://www.youtube.com/watch?v=sJsIF1vwH3o

The YouTube guy talks about what he did to support the weight of the new Corsair power supply.