hey, im new to linux. i had start using linux from a few days n had installed Helix Player and a Modem driver, but now i need help, im stucked while installing avast4workstation-1.0.8.tar.gz which i had downloaded from avast.com. i had successfully extracted files when i try to install it gives me error like "no permission" so if u can give me full help regarding this i will be thank full to u?