PcLinuxOs KDE 64 bit - bootloader on the same partition

Hello. I downloaded and mastered PCLinuxOs 2017 - 64 bit kde. I have this situation on my pc: sda - data disk - ntfs sdb - data disck - ntfs sda in which there are:

- sda5 - Ubuntu 16.04 - ext 4 - sda6 - Data partition in ntfs - sda7 - ext 4 partition where I desire install PcLinuxOs - sda3 - Win 10 partition - ntfs

• sda1 - swap
• sda2 - extended partition containing inside:

Currently I have Ubuntu 16.04 installed in sda5 and Win 10 installed on sda3. The boot is managed by the Ubuntu grub, installed in sda. I launched the installation of pclos following the directions on video, allocating it on sda7, but it does not give me the opportunity to decide where to install the bootloader (which I want to put in sda7, and then manage everything with the Ubuntu grub). In fact, proceeding with the installation, a window appears where I can choose the position of the bootloader but, strangely enough, it leaves me only three choices: sda where Ubuntu grub2 is installed. sdb - data disk sdc - additional data disc. It does not let me choose sda7 which is the partition where I installed pclos. I do not understand why I can not install the bootloader in the same partition (sda7) where I want to put PcLinuxOs. I have therefore aborted the installation and here I am to ask you a little help. Thanks in advance

ps. sorry for my poor english

If it uses grub to boot, install it to the data disk. It only writes to the MBR and a few sectors after the MBR (if MBR(msdos) and not gpt).

Or you can install to drive, and then load Ubuntu and reinstall its grub to MBR. Or use Boot-Repair to reinstall grub. https://help.ubuntu.com/community/Grub2/Installing#Fixing_a_Broken_System

Boot Repair -Also handles LVM, GPT, separate /boot and UEFI dual boot, only use ppa download into Ubuntu live installer. https://help.ubuntu.com/community/Boot-Repair

Thanks for replay. My fear is to compromise access to the data disk (eg sdb) if I install the pclos bootloader on sdb

Ok thanks to all. solved thanks to a friend (dxgiusti) as per link. https://www.dropbox.com/s/5y34r6pyeolcmfc/dualboot.mkv?dl=0