yep your not wrong! i wish i had built my own with what i know now. i know the windows is OEM but that doesnt bother me.
My warranty is already void i changed a few things due to dell putting crappy parts in, this is what ive done upto now, the case to a antec 902, corsair 650w psu, gigabyte 470 gtx gpu and LG optical drive which was quite easy and i enjoyed it the only thing that needs changing is the mobo to be practically a new build! i have the money aside for another retail copy of windows 7 as i sold all the old parts
I really do wish i had gone down the new build route but i wasnt confident enough at the time, a new build now would be the only option for me!
Thanks