Shahab, Which AVG product are you actually attempting to install on your system?.
AVG Guru
Formatted my PC and tried reinstalling AVG, but now i get an Error code: 0xC0070643.
how do i fix it?
Shahab,
Can we confirm that your issue has been resolved?
Thank you.
thank you both and hope nothing else pops up anytime soon 
Shahab, Which AVG product are you actually attempting to install on your system?.
AVG Guru