My situation is that i have 2 hard drives. One of them is the main hdd that i installed windows on and second one is 500 gb old hdd that i dug out of my old PC and i use it only for storage since it's slow and makes noises when working. But the thing is, i noticed that whenever i install linux it installs it to this second disc and basically lags and freezes whenever i use it. I also don't know the size of the first hard drive since my partitioning and messing with it caused the wrong size to be displayed, but i think it's around 150-200gb.
What i want to do is: completely wipe everything on my main drive, remove windows, restore the hdd to factory settings, then i want to run xubuntu and win7 in dual boot(where xubuntu will be my main system and i only want a small partition for windows since i will only use it when i need to). So can anyone tell me the best way to restore my hdd to factory state, and to make sure that when i install both system they actually install to the same hdd?