I'm going to apologize just to start off, I have never replaced a PSU before. My old Compaq PSU went out and I'm trying to buy a replacement but I'm not really sure which brands are the best/most reliable and cheap. The model # on the PSU is Compaq 266503-001. If I need to provide any additional information, let me know. Any help anyone can provide would be great. Thanks in advance!
I think that thread is a great place to start. I completely agree with their recommended brands and I would encourage you to stick with one of them. If you could post your system specs, I think that would greatly help us recommend a specific wattage. I agree with the previous posters, if you have a more basic system, a 400W PSU should be more than sufficient. If you have a higher-end system with a discrete graphics card, you will probably need more power than that. Hope that helps!
Most rigs will have the same PSU size and shape so it is just a matter of buying one that is powerful enough for you without blowing your budget. I am running a 660w PSU for my budget gaming rig and it is just fine. Once you have the one you want, simply unscrew the old PSU, plug in the new one, and connect all the leads just the same. Once you set up your first PSU - or any other computer component for that matter - doing it again is child's play
It has more than enough power and is a very highly rated brand. As Klosteral said, all you have to do is disconnect all the cables (make a note of where they all came from), and unscrew the PSU from the back of the case. To install the new one, just use the same screws to reattach it to the case, and then hook up whatever connectors you disconnected.
Note: on the PSU I recommended it has something called a "20+4 pin main power connector". This allows the PSU to be compatible with more motherboards. In your case, you would just use the block of 20 pins and leave the other 4 off to the side. Good luck!
Im gonna vote against that Antec Basiq 350W unit, antec makes some good units, the basiq line is their cheapest units, some of them have been redone to be higher quality but the red switch on that one tells me it is still the old super crappy design. The Corsair 400CX is slightly more after rebate and has wayyy more power than the basiq, 30A on the 12V rail vs 23A, its also a much newer design with active PFC and is 80+ certified, that basiq unit is just that, the sheer basics. http://www.newegg.com/Product/Product.aspx?Item=N82E168...