Changing C: partition (Boot) from Primary to Extended

Hello,

(yes I know, "yet another one on this subject" , but please bear with me...)

I am trying to create logical drives, and to that end have to turn a primary partition into an extended one.

Currently I have four Primary partitions (yes, you see it coming... ):
*: SYSTEM (no drive letter, marked System, Active),
C: (no name; marked Boot, Page File, Crash Dump),
D: Recovery, and
*: HP_TOOLS (no drive letter)

I am following (of course) the excellent and rightly famous tutorial here,
and I have to use "Method Two", because I am in exactly the situation described there, namely that the manufacturer (HP) greedily has created four primary partitions already, so that I cannot simply add another one. (And I don't want to touch, let alone delete, SYSTEM and/or Recovery).

The problem is that I was trying to use not the Partition Wizard mentioned in the tutorial, but a similar tool called EaseUS Partition Master.

However, when I told it to turn the Primary C: partition into an Extended one, it refused on the good grounds that this is the Boot partition and can therefore not be touched.

It makes sense, and I am "almost" certain I understand the reason, but before I do something stupid*, I'd like to have this confirmed by someone who knows this stuff better...
(My confusion stems from the idea, apparently wrong, that Active partition means the same as Boot partition; so with SYSTEM as the Active partition, I was kind of surprised to find that actually C: is Boot.)

Questions:

1. The essential difference seems to be that EaseUS Partition Master is run within a "normal" Win7 session (i.e. having booted from the hard drive), whereas for using the Partition Master (as per the tutorial) one apparently must boot from a CD.
Is this understanding correct?

2. Does that mean that the C: partition in the latter case (booting from CD) is not the Boot partition, and therefore can be changed to Extended (without reformatting, of course)?

3. When I afterwards boot "normally" from the hard disk again, will C: then operate OK as Boot partition (or rather volume now) again, even though it is now a logical volume on an Extended partition?
(This is the question that worries me slightly. There are numerous threads here about this "all primary partitions taken" issue, and I must have read them all; but I couldn't find a clear answer to this last question.)

All this is actually made rather clear in the tutorial, at least implicitly (see e.g. the last screenshot, under Step 4 of Method Two); but I'd still appreciate some explicit confirmation.
It's not my own laptop I am setting up, you see, and I'd hate to mess it up...

Many thanks for your time and help!

Cheers,
tronje

* I do already have (via MacriumReflect) an image of all partitions, plus the corresponding boot CD, though

I don't know about EaseUS.

Yes, if you use Partition Wizard boot disk, it will operate outside of Windows.

The system partition is the partition containing your boot files. Boot partition is the partition currently booted---C in this case. Boot files are typically not on C in a standard installation, but can be placed on C if desired. That's where mine are.

It's OK for C to be logical. It's one of the ways to get around the 4 primary partitions maximum issue. Logical partitions are not primary.

I'd advise you to use Partition Wizard bootable disk.