Maximum PC

Hello everyone. Forgive me if I am posting In the wrong place i figured this was best for my problem.

I am currently at a dead end. I have a Dell Studio 540S Slim and I want to upgrade it. Not so much for gaming(though it would certainly be a plus) but more for editing HD video. Right now my computer cannot handle the editing and it can barely handle some games even on the lowest settings. The only thing is I am not sure what can be done,or if anything can be done with this computer.

Here are my PC specs:
-Vista Home Premium 64 bit Service pack 2
-6.00 GB RAM
-ATI Radeon HD 3400 Series 2041 MB
-Intel(R) Core(TM)2 Duo CPU E7400 @ 2.80GHz
-250w power supply

The problem is the slim version of the 540s are only 3 1/2 inches wide inside the case and I have found only one other power supply besides the stock 250w that would almost fit. It was a 400w, which with any video card in my budget is not good enough. The 400w is $100 and if I got it not only would I have to cut a harness tab off the inside of my case I'm not entirely sure it would clear the mother board height wise.

I took measurements of my case.

Without modification to case:
-----------------------------------
Width=3 1/2''
Height=3 1/8'' exactly
Length=8 1/8''
-----------------------------------
With modifications to case:

Width=3 1/2'' (No modifiable)
Height= 3 1/8'' (Not modifiable)
Length= 9 1/8''
-----------------------------------
There is no way I am going to spend $100 on a 400w power supply that I'm not sure will even work. Its just too tight of a fit. Especially since I know I can get a bigger wattage supply for less money.

I had read online and have seen some pics of people running external power supplies,basically a regular power supply but hooked up outside of the case. I would really like to know if this is something I can do. I have read that with some pcs the power supply is positioned so the psu fan also helps cool the rest of the case. If I can get some sort of harness that extends the power supply harness,I would make a little stand and a ventilated box for it,I would also install a fan where the old power supply was located to make up for the loss of cooling.

Buying a new comp is out of the question. Buying a new case is also out of the question because apparently the slims are made in a way that the components inside cannot be transferred to a no slim desktop case.

Besides stating my problem I have a few questions:

-Are there harnesses for power supplies that have female and male ends for each plug so it extends the original PSU harness to the components?
-Are there power supplies that by themselves have a long harness?
-Has anyone here done an external PSU before?
-Is a computer harness any different then a cars computer harness? I'm asking because if I cant get a longer harness I was thinking about just purchasing a PSU and extending it myself. I can wire cars,would it be any different?

Any ideas...?

That would work just fine, I have done similar projects where I slapped in a second PSU to handle additional load simply because I was too cheap to purchase a newer unit when I had ones laying around that worked just fine



In both cases I just tied the grounds together all the hot + leads were independent, one would power up the board and the other would power the components. Since you are doing a direct PSU replacement just make sure the wiring matches and you won't go wrong.

cheers!