Or I should ask how helpful and benifitial will it be to start with C++
This may seem irelevant but it has some significance for me,may be few others like me.
I just want to know ,How Important is it to Learn C++ , COM and ATL while you are a .NET programmer?
I love programming with .NET and C# .Visual Studio just has it's own charm of intellisence ,Color Coding and other pretty features , which make us addicted to it.
I was thinking , almost we can build anything with C# and still it holds true mostly, but it lags sometimes like:
While I try to create a Shell Extension , then it is highly suggested to use unmanaged code instead of any managed code. Also there are few other things like COM , ATL , which are preferred to be coded in C++ rather than C#. I am just 4 years in IT industry and love to be Solution Architect.
So need all your inputs to know , how important/helpful will it be in my future venture if I am doing my Current COM Project with C++ , which integrate with .NET UI.
Is there any implementation of C++ and .NET in common domains like Health Care, Banking and Telecommunication.
The issue (at least for the specific cases you mention, such as shell extensions) with trying to "integrate with a .NET UI" is that you really can't. The reason it's not a good idea to write shell extensions in managed code is that a given process can only load one version of the CLR at any given time. If two shell extensions depend on different versions of the CLR, and they both try to load at the same time, it will fail. You can't load the CLR in any way shape or form in the context of your shell extension and be a well behaved shell extension.
My advice would be to not bother with C++ until you really have a reason to learn it (despite that C++ is my favorite language). But when you do learn C++, leave your .NET baggage at the door. There are lots of things (such as excessive use of casting, constantly using new, etc) which are idiomatic C#, and are just plain wrong in C++. You will be a lot happier if you don't try to understand C++ concepts in terms of the CLR -- simply because C++ doesn't run there. You can use some of the design patterns you may have learned for C#, but how the underlying language and machine operates are completely different between the two languages.
Probably the most confusing difference for new C or C++ programmers is the concept of undefined behavior. The C and C++ standards are written in such a mannar as to not be tied to a particular machine. This is in stark contrast to architectures like Java or .NET, where the language is actually defined in terms of a virtual machine (and therefore is extremely dependent on that VM). This leads to places where the standard literally does not say what the correct output of a program should be; and instead says "however the underlying machine usually does this". You'll probably notice this quite a bit if you're ever dealing with floating point math. While C# has strict and specific rules about how and where floating points are calculated and rounded, C and C++ make no such qualifications.
Once you understand C++, then you can move on to COM and ATL. COM is essentially designed to make a C++ like class structure accessible in a language (the COM ABI), machine (marshalling between 32 bit and 64 processes on the same system, etc), and location (DCOM provides RPC facilities) independent way. If you don't understand the C++ object model, then you're going to have an extremely difficult time with the COM object model, because the two are extremely similar. ATL is a set of C++ class templates around COM fundamentals which simply handle some of the boilerplate for you.