Okay so I'm trying to format my hdd to ntfs on Ubuntu 13.04 and it gives me two options, Don't overwrite existing data(Quick), and Overwrite existing data with zeroes(Slow). What does it mean to overwrite the existing data with zeroes? I plan on installing windows 7 but it says my hdd must be in NTFS format. Please help me with this.Thanks in advance.
The overwrite with 0's will literally write #FFFFFF to every sector on the harddrive, permanently erasing the data that was there. This is a technique used to remove all data fragments which might be left on the drive. It's usually used when pernicious malware is expected or as part of a data-wipe routine.
Chances are, you just need the quick option.
If it is SSD, you only need to overwrite it once for security since it is not magnetic. Overwriting it several times is bad for SSD's. Also, use MBR then NTFS if you plan to install windows. Regards.