How are you programming the PIC16F84? With what programmer?
After programming have you ran a "verify" to ensure the program is correctly stored in the flash?
What RC values are you using for your RC OSC?
It looks okay and simulates okay. If your hardware is alright, it should work. Take a look at your RC oscillator, if you configured it correctly, etc. You might try with a crystal and change the config bits in the code to a crystal.
actually i am making a digital combination lock and multisim only have pic16f84. in multisim pic work ok on 8 KHz . i have tried that code in mplab and it is working fine. The clrf also working fine in mplab. now on 8khz it is also fine with multisim. Thank you so much for help me
bye