I built my own for the first time last year off a 10 year old computer I had been using for some time that originally had XP on it.
I had a couple of standby computers around in case I fucked this up, but it was a mini ATX ( I had to learn what that was ) and I researched all the original parts based on the model and brand numbers I could find on the case to learn what I even had. Once I knew what I had, I started to research each major part and what I could "swap" out and replace. Once I did this, things started coming together in my head how I could do this.
Once I learned I could replaced the whole MOBO I realized I could redo everything.
I replaced the Mother Board with another Mini ATX sized one. I didn't care about getting the newest or best, I knew anything I got mid-grade would be 10000x better then what came in this 10 years ago new. The only requirement I had was it had to be Mini ATX, fit a AMD chip and have some of those older slots ( for my wifi card and graphics card )
Ordered a new AMD chip that I could overclock, it was some kind of "black" edition amd and also ordered a fan for it and thermal paste
Reused an older graphics card that was still newer then the 10 year unit I bought ( i replaced the graphics card once already ). It was some 8800 GT that gave me 2 monitor ports, so I reused it and overclocked it this time.
Reused my memory sticks ( newer then the 10 year old unit )
Hooked up a couple reg hard drives ( non SSD )
Installed Windows 7
Used all the old fans
I basically upgraded some parts and reused others and I got a huge performance boost. I never did hook up all my USB slots and didnt hook up my cd drive and shit. I also never put the cover back on and it sits on my desk like a jumbled mess of cables for about a year now. I blow out the open case about twice a year.
I just never got around to finishing it once I got it to work and started using it.
I would like to finish it up by:
Installing new memory sticks
Installing an SSD
Installing a new graphics card
Getting a bigger case to fit all the cables from the new PSU.
Getting one of those clicky mech. keyboards
I got couple "slim" profile computers laying around I would like to repurpose too, but I am not sure where to find these slim parts or what they are called ( the PSU is like 1/4th the size of a normal one, same for some of the cards inside ).
I got a couple more mini ATX's too.
Whats a good higher end, decent ( but not top of the line ) MOBO and chip combo these days? graphics card? its hard to stay up to date on this.