Msconfig problem (avast) and Mode

hi to all I wanted to use Safe mode but msconfig (and avast) refused (error refused access has been dismissed when attempting to change a service. you may need to log in using a Administrator account to make the changes specified) and I see more avast popup 3 :

- Write access to the registry key \ REGISTRY \ ... services \ avast! Web Scanner \ refused

- Write access to the registry key \ REGISTRY \ ... services \ avast!
antivirus \ refused

- Write access to the registry key \ REGISTRY \ ... services \ aswUpdSv \ refused

so I think this is indeed a service but which (the msconfig and attitude avast PREVENTING safe mode. see the following link: computer problem.
Thank you for your help!

more spyware terminator is a backdoor.vb.fnl me in:
c: \ windows \ system32 \ MSWINSCK.OCX (122K Active X control version 6.1.97.82)
but I dare not remove it (which a priori is important for the stability of the system) for fear that it is a false positive because I've analyzed the Malwarebytes and avast and a-squared which have found nothing.

Hi,

the whole team security forum you will confirm: Avast is a real colander.
It is imperative to use free antivirus Antivir.

Begins with Avast uninstall cleanly. You have a firewall on your PC?

it's a pain to uninstall avast, I am using firewall against my personnal Kerio firewall.
if I had to change their antivirus antivir I wonder if it is heavier or lighter than avast, thank you

why you say proper for avast?

ok I'm gonna change for antivir but I want to know if I am infected nyt is no risk that the virus spreads among UNINSTALLATION of avast and installation of antivir?