Again the answer is no.
This issue is well discussed and unless you wipe the drive thoroughly with something like DBAN (beware, it really wipes it out) you risk leaking information. If you don't believe it, that's fine but I'd like your system please.
As to the gift machine. Truly make it a gift. Let them install Windows fresh.
I wish to format a hard drive before giving a computer to a charity. Can I do this without removing the operating system, XP which was installed as an upgrade to Win 95.?