How to properly uninstall Ubuntu?

Question

linux

Good afternoon. Please tell me how to solve the following problem:
There was an attempt to install Ubuntu next to Windows-7. For this, an image was downloaded from ubuntu.ru/get, version - 18.04 LTS (Bionic Beaver). I recorded the image on a USB flash drive, I install the system. After about 15 minutes of installation, a command line appeared with a lot of errors, the laptop went into reboot. At the moment, when I restart the laptop, I do not see a window with a choice of OS (Ubuntu or Windows) - Windows immediately loads. The problem is that the hard drive is now occupied by these 60 plus GB. How can I correctly delete a partition from Ubuntu? Tried to write to a USB flash drive with "system recovery". I did it according to the guide, just using system restore, entered "bootrec.exe / fixmbr bootrec.exe / fixboot" into the command line. Through the view and manage disks in Windows, I do not see anything but my C drive (in theory, Ubuntu was installed on it, but there are no options for deleting a subsection in the C drive).
Who faced it? There was an idea to just try to install the system again, but is it sure that it will overwrite everything in an already occupied partition?

Answer 1

Ubuntu LiveCD must be Gparted.
Or in Windows Computer->Management->Disk Management

Answer 2

In general, I solved the problem like this:
Installed Akronis, combined the "free" space with Disk C. As they say - inattention.
Thanks Sanes :)