Installation doubt - multiboot w/W7

Hi all,
I have a laptop with W7 and Ubuntu 16.04.2, both 64 bits, on dual boot.
Ubuntu was installed few days ago. It is running along with W7 but have some glitches (not related to dual boot).
I tried Ubuntu Mate from a CD, and having had a good impression of it , proceeded to install it.
The “Others OS” were detected and I choose to install alongside then.
I was offered to resize partitions. But by the sum of the sizes offered I concluded Mate would be installed in W7 partition. And what about 16.04? Will the sda3 extended partition be maintained and 16.04 included in grub menu?
My partitions are:My HD partitions are:
Device Inicialize Start End Sectors Size Id Tipo(kind?)
/dev/sda1 * 2048 206847 204800 100M 7 HPFS/NTFS/exFAT
/dev/sda2 206848 799921454 799714607 381,3G 7 HPFS/NTFS/exFAT
/dev/sda3 799922174 976771071 176848898 84,3G 5 extended
/dev/sda5 799922176 968581119 168658944 80,4G 83 Linux(ubuntu 16.04.2)
/dev/sda6 968583168 976771071 8187904 3,9G 82 Linux swap / Sol

I am not sure what Mate will do with sda3 and its contents and if 16.04.2 will appear in Grub startup menu.
I am afraid things get corrupted and loose a lot of time reinstalling W7 and Mate (and perhaps 16.04.2).

If I can install all applications I want ( not that many, and by what I have seen on internet, there will no problem) , and Mate behaves properly I intend to erase 16.04.2 partition (don’t know if there is a proper way to uninstall it) .
Will have to repair W7 boot and install boot-repair on Mate (is it possible?).

Thanks for any help,

Don’t know why the partitions numbers about sectors became a mess. I have copied from terminal( fdisk -l) and pasted in my post. All seemed ok. Anyway the numbers are not that important in the context of my post (hope so).

Some tutorials that may help.

The tutorials were very very helpful and Mate is running OK along w7 and Ubuntu16.04 .
I am having difficulty in installing Lazarus, but people from their forum will certainly help me (has they have already done). Anyway, if you have any hint please send it to me.
Thank you very much.

Very good :slight_smile:

Since multiboot is solved, I have marked your thread solved. Please start a new thread on a new subject (Lazarus) if you want, but your probably in good hands at their forum :wave: