I have a Dell XPS410 that I purchased back in 07. I've changed the graphics card to a GTX470 completed 4GB of Nvidia RAM and added a new PSU plus 3 fans. I still have the same Q6600 Processor overclocked to 3.0 I once wanted to put a thermaltek tower but any cooling tower would not fit properly in the BTX design it appears.
Recently I wanted to overclock my CPU past 3.0 and since I can't figure out a way to change the voltage on an intel motherboard (P965 express chipset) I have grown interested about changing my motherboard for a newer ATX type motherboard. (I would have to switch the Case of Course)
I can run every game (Metro/BC2 lol) perfectly with avg 45FPS but I want to upgrade for the future and remove those walls preventing me from better such as RAM, and a better CPU some day.
I want this so that I can not only continue with my current DDR2 Dual Channel Ram, CPU and GPU, but add another 4GB of RAM plus a Thermaltek tower for better cooling as well as being able to control the voltage in the Bios.
I would like to know if all of my current hardware would be able to do this transition without a problem from a BTX type case to a ATX type. Also I would like to ask for suggestions on mid size tower or full size. Motherboards with a range of $50 to $99USD (Cheap because any board will kick my current's behind easily) with a good versatile Bios for all the kinds of tweaking.
the antec 300 is a good case, CM 690II for a few dollars more is also very good.
switching out all your hardware should be fine once you get the ATX mobo, if you are using the DELL OS it may have an issue with a new mobo. I did something similar a while back but installed a new OS.