[yamawho]

You are having a bad day I gather ...

It depends what you are comfortable in doing.
Don't have another system to work from ?
If you do then put the hdd in that one and boot from the other.
Then go right click on my computer, select manage, disk management and then delete the partitions on that hdd.

If you don't have a 2nd system to work from, then download a linux distro like ubuntu or linux mint and use the hdd tools within. This distro's will run as a live cd and not install to the hdd. Depending on the apps offered there is gparted, qparted etc ...