"Undoing" Dual-Booting

[Zonus]

My brother recently decided to try dual-booting, since he wanted to try the Linux environment. When he was asking me about mounting an ISO to his USB drive, I sent him the link to the software I did it with and also a link to Elementary OS, to see if he would like to give that flavor a try. 
Fast forward a couple of hours and Elementary OS turned out to be disappointing, and he now wishes to "uninstall it". I explained to him that he would have to delete the partition that he installed Linux on. Problem is: He/I/We can't find it.

He has 2 drives in his PC. The primary being a 1TB, and the secondary being a 500GB. When we checked for partitions, he only had 3. One reserved for the system, and the 2 others being the drives. The 2 drive partitions are nearly full size. 

Why can't we find the Linux partition? And more importantly, how do we delete it?

Thanks in advance.
-Zonus

[Flyguygamer]

He may not have installed it and was running from the usb stick as a live cd os.

[Gas_Mask_]

He may not have installed it and was running from the usb stick as a live cd os.

Im with fly in this one, but he could have also installed it under windows. I know that some distros let you install it as a program if you alredy have windows.

[gkubed]

What are you trying to "find" it with? Whatever software you're using may not recognize an EXT4 (or whatever you're using) partition.

edit: I'd recommend the gparted live USB/disk

[Flyguygamer]

Im with fly in this one, but he could have also installed it under windows. I know that some distros let you install it as a program if you alredy have windows.

May be that too. Post a screencap of C:

[Gas_Mask_]

May be that too. Post a screencap of C:

Its most likly under C:\ProgramFiles\ somewhere. I used to do that with Ubuntu, and Mint, untill Mint dropped support for that. (this was like 2 years ago)

[Flyguygamer]

Its most likly under C:\ProgramFiles\ somewhere. I used to do that with Ubuntu, and Mint, untill Mint dropped support for that. (this was like 2 years ago)

I once had it under C:\Ubuntu

[Gas_Mask_]

I once had it under C:\Ubuntu

You can specify where to put it, but it defaults to programfiles.

[Flyguygamer]

You can specify where to put it, but it defaults to programfiles.

Never had that. Not really important. 

Just waiting on @Zonus to come back with a screenshot of C:\program files, C:\ program files x86, and C:\

[Satlen]

It will not be in C:\ guys, he probably just ran it off the usb stick without realizing you have to install it.

[Zonus]

Never had that. Not really important. 

Just waiting on @Zonus to come back with a screenshot of C:\program files, C:\ program files x86, and C:\

It will not be in C:\ guys, he probably just ran it off the usb stick without realizing you have to install it.

Its most likly under C:\ProgramFiles\ somewhere. I used to do that with Ubuntu, and Mint, untill Mint dropped support for that. (this was like 2 years ago)

He did install it, it still gives him menu on start-up whether he wants to launch Linux or Windows 8.

He did install it "alongside Windows 8", but we haven't seen anything in either "Program Files" directories.