Really? Then I would listen to the 7 people who have already told you to just format when you reinstall Windows!
If you want to irreversibly format your computer, and everything on it, then leave it in a room with a 5 year old, complete wipe for you for free.
But seriously though, when you format the drive with Windows then it will delete everything on it, but 3rd party software will probably keep something of itself on there which by the sounds of it you don’t want. So just format the drive, and reinstall Windows.
If a virus is the reason for this, then download AVG Anti-Virus software, it will find and remove any viruses with no formatting necessary.
I don’t mind if the data is still there as long as the viruses are disabled and can’t do anything, to fuck my system up.
Just do whatever you want. Seriously, if you’re so Hell-bent on Killdisk, just use the damned thing already. It will take longer and you’ll basically get the same results than if you just did a regular Windows installation format, but whatever, I’m tired of trying to save you some time when you won’t listen. So, for the umpteenth time, it doesn’t freakin’ matter!
Viruses are files themselves… if you do a standard format (with the windows installation cd, for example), the viruses will be wiped, just like ALL other files on your drive. Sure, the FBI could recover the viruses on your hard drive, probably, but that’s beside the point.
Edit: oh, and install an antivirus next time 
(I recommend AVG free, it’s free and it works perfectly fine)
I’m using spyware doctor review here, https://www.howtogeek.com/reviews/spyware-doctor-antivirus-2010/ Also i’m going to do it the way you guy’s said.
I personally like Avira. It works, and it’s a lot less bloated than some of the other antivirus programs.
https://www.avira.com/en/pages/index.php
As for getting rid of viruses, you can wipe your HDD, but it’s like smashing a cockroach with an artillery round.
Get antivirus, run it.
Open your command prompt and run these two things for good measure:
chkdsk /f and sfc /scannow
Stop downloading CP.
Problem fixed.
so the viruses will come back? And what do these commands do? Also here we don’t have FBI.
Run: cmd.exe
Type: format C:
Lol. Or just slip in the OS disk you have and choose to install the OS, during the startup sequence, you’ll be allowed to work with partitions, during which you must format any parts of the harddrive (in your case, the whole thing) going to be used.
I wouldn’t recommend using any drive-wiping program, cuz it seems mostly superfluous.
I just recently wiped my old computer, and I was a little confused when some drivers I hadn’t expected to survive still existed. Turned out some of them were hardcoded into the mobo or something along those lines. There’s no way to write data (viruses) there, so it’s not at all a deficiency of the wipe, or can it be reached by any other wipe without possibly fucking your computer over, even if it were possible.
EDIT:
Oh, and what he’s saying about smashing cockroaches with artillery rounds is that: This is mega-overkill. Unless you’ve been very… active in your fwaping recently, and your harddrive is just filled with general death and chaos.
Edit edit:
Now, if you’re whiping your computer to hide something, you’d have to take some extra steps. Because “deleting” data always ends in some wasted energy (in this case useless storage/data) that could possibly be re-pieced together by somebody who really wanted to get that data. You’d want to refill your harddrive with random crap (a self-propagating text file or reproducing WoW shortcut [that happened to me, my worldofwarcraft shortcut copied and pasted itself enough times to fill my entire harddrive with a bunch of 1.7 kb files of doom. The installer was fucked]) would do), then re-format again. Do that four times and your computer is wiped to professional/political standards.
Not deleting to hide just want to kill those motherfucking viruses for good.
Formatting to get rid of virues is like getting rid of a cockroach with a nuke.
The viruses are definitely not coming back if you don’t have any backups.
edit: unless you also have viruses on a flash drive…
Nope no viruses on my flash drive I’ve already scanned it.
Ahh this thread made me laugh so much.
Right…
When you format your hard drive you will delete all the data on it. a virus is data. so once you format it wont be there any more.
3rd party applications are great for formatting and get rid of data securely so it cannot be recovered, but this is only needed if you are going to be getting rid of your hard drive or have something to hide. So for your purposes just use the built in windows formatter on the windows installation disk.
Once you wipe your entire drive with the windows installer and reinstall windows. you will have NO viruses. At this point please download and install an anti virus like AVG or Avast or one of your choice if you don’t want to take my recommendations.
Congratulations. You now have a computer with NO viruses. Watch what your downloading and what you are putting into your PC.
Malwarebytes is enough for me.
But some viruses make transfer you from the Malwarebytes website to some more viruses.
Just to stir some more, formatting the drive is enough as long as the virus doesn’t live in the boot sector… But any decent AV software checks for that too - I’d suggest an offline check tho - once you’ve booted from a drive there’s no sure method of knowing what’s hiding on it.
:facepalm: :’( 
Maybe it’s a special cockroach, like neo from the matrix.