What is the use of mscorlib.dll in .net?

Answer 1

It's the main dll for the .Net framework. It should come in your installation (obviously), and in 2.0 it's installed to the GAC.

Answer 2

It is the main dynamic link library in .net, Or in other words its Microsoft's Common Object Runtime library for the .net language

Answer 3

this is the main core library part of .net run time environment

eg.
for reading and writing into registry we use mscorlib.dll
#using
using namespace System;
using namespace Microsoft::Win32;

// This is the entry point for this application

int main(void)
{
RegistryKey * pRegKey = Registry::LocalMachine;
pRegKey = pRegKey->OpenSubKey(L"HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0");
Object *pValue = pRegKey->GetValue(L"VendorIdentifier");
Console::WriteLine(L"The central processor of this machine is: {0}.", pValue);
return 0;
}