Intel HD Graphics + NVIDIA Geforce [Drivers & Usage problems]

I use Toshiba M645 Laptop that has two graphic cards
with NVIDIA Optimus Technology. (Auto-swicthing graphics processors)
Now I have some vga problems and driver questions below:

1. Intel HD Graphics <-Why can't install driver from Intel official website?, driver not supports!
, but the driver in Toshiba website can be installed fine as well.
What's wrong with that? Was it mean "Intel HD Graphics" has more than one type, several of model classes?
or it must related to the chipset of Toshiba laptop's mainboard?

2. NVIDIA Geforce GT330M <-How to use only this vga stand alone?, I tried to disable Intel HD Graphics from device manager
and then the monitor was not in use, black screen was displayed.
So, I tried to disable Intel HD Graphics in safe mode, no black screen
, but the next normal boot it was displayed like GT330M was not in use
(can't config NVIDIA tools, it was disappeared from control panel), but it was still enabled in device manager.

Now, I just updated Intel HD Graphics driver, a mouse lag in Aero themes taskbar effect was fixed,
also the video framerate fault was fixed too.

Hope someone can give the solutions, how to fix these problems.
Thanks in advance.

My Laptop: Toshiba Satellite M645-1014X

OS: Windows 7 Ultimate x64 OEM Toshiba
CPU: Intel Core i5 M560 2.67GHz
RAM Samsung 4GB 2x2 Dual Channel
HDD: Hitachi 500GB
VGA: Intel HD Graphics, NVIDIA Geforce GT330M 1GB
SOUND: Realtek High Definition Audio

1. Main reason the Intel reference driver won't work is it hasn't been modified to work with the second card (applies to laptops with either Nvidia or AMD for the second card). Same applies to the Nvidia driver, it requires the Intel driver to be installed before it can be installed.

2. From what I have seen the Nvidia card (or AMD if so equipped) can be made to run all the time only when the laptop is plugged in and you change the power settings to high performance. If that doesn't get it working all the time here may be another setting that needs to be changed. If that is the case going to have to wait on someone with a similar setup for more info.