If you want to wipe the disk then you can do it within a command prompt using the install disk. See option one here.
At the command prompt type
select disk X where X is the disk you want to wipe
clean This will delete the partition table or you can use clean all which will zero the disk so make sure you have selected the correct
disk if you have multiple HDDs, Clean all takes a long time on a large capacity drive.
convert gpt use this command if you have the new UEFI/GPT disk. If you get an error ignore it. You can determine GPT by opening a
command prompt of your current install and typing the above first two commands. At list disk you should see a * under the GPT
heading of your system disk. You can also look at Disk Management. An EFI partition formatted FAT32 would indicate GPT.
Now proceed with the install. The above commands work for 7 and 8 but I cannot confirm if Microsoft allows this for 10.