Interop Vs Object Managment

There are no such alternatives. Not clear what do you mean by "Object management".

The problem is simple: some access to hardware information can be provided by .NET libraries, but a lot more is only accessible through a the native OS. Essentially, nearly everything is accessible via Interop (P/Invoke), only a part of it is bundled with .NET Framework and placed in GAC (Global Assembly Cache) and some you have to do by yourself.

See:
http://en.wikipedia.org/wiki/P/Invoke[^],
http://msdn.microsoft.com/en-us/library/aa288468%28v=vs.71%29.aspx[^].

Another thing you need to know is WMI and Hardware Inventory:
http://en.wikipedia.org/wiki/Windows_Management_Instrumentation[^],
http://msdn.microsoft.com/en-us/library/system.management.aspx[^],
http://technet.microsoft.com/en-us/library/cc180952.aspx[^].

See also this CodeProject article: WMI Hardware/Software Enumeration Script[^].

The rest of it depends on what hardware are you interested in and what kind of information do you need.

—SA