Pallavi, what inputs do we have to solve the problem? Any of the following would do -
1. specs sheet of the proc
or Opcode sheet of the processor
2. OS specific - in windows - start->run->dxdiag - the main screen will show you what proc you have
3. OS specific - in linux - "uname -a" will show you what proc you have
4. OS specific - in linux - "grep flags /proc/cpuinfo" and look at the end of the string - lm = 64 bit, real mode = 16 bit, protected mode = 32 bit