ERROR 0xC0070643

i"m using windows 7 ultimate with AVG protection trial.
i tried to switch to AVG FREE but i have 0xC0070643 error code while installing.
i try avg systool, reinstall, and .... installation failed  again.

if you couldn't help me to solve that at least please help me to uninstall avg?

Hello Reza,

We are sorry for the inconvenience caused.
Do you have any other third party antivirus program installed on your PC?