[Swoorup]

I think this is a general topic so I am posting here.
Whenever a program tries to execute invalid instructions
For instance: Supposing esi is 0x00000000
mov ecx, [esi]

This would cause crash and display an error handler message. And the program would end.
My question is: Is there a way to replace the standard crash handler with one of my own?
I would like to include much crash messages as possible. Values of registers, Stack, etc

[K^2]

There are some kind of errors you can handle using try/catch blocks, but specifically what you are talking about is a segmentation fault, and no sane OS would let your program maintain control if it seg faults, so the error message you get will contain what OS devs thought you should have and nothing more.

If you aren't familiar with protected mode and its specifics, read up on differences between protected and real modes of x86 family of CPUs.