Hello!

I have NVIDIA nForce2 Ultra 400 motherboard. I can't determine from which manufacturer is my IDE controller. How to tell? Is it VIA IDE controller? Maybe ALI IDE controller? The thing is that if I have, say, VIA IDE controller, I shall remove all the other IDE controller components with nLite, so I'll remove ALI IDE controller and Toshiba PCI IDE controller. I want to get rid of that unneeded things. Please assist me in determing the manufacturer name of my IDE controller. Thank you. And merry Xmas!

Try PC Wizard or SIW.  You should be able to at least get your mobo make and model so that you can check the technical docs on it.

This sounds like a joke ... however, NVIDIA is a chipset maker. IDE controllers are part of a chipset. Which company is the maker of that particular motherboard is irrelevant. You don't need the other drivers - VIA, ALI, Toshiba etc.
If you want to learn more details about you computer try Everest Home Edition.

Right.
You can typically choose between using the reference chipset drivers or the mobo vendor drivers.  And different people have different skill and knowledge levels.
They aren't distributing the Home version anymore so you may want to consider finding an alternative.