Avast Premier didn't open anymore, now i can't reinstall

[julipun]

Hi there, i'd be very glad for some advice.

I am using a Win7, 64-bit System. My Avast Premier didn't open anymore. On the lower right side of the screen, the SecureLine-Icon vanished completely, the avast icon sometimes showed, but vanished when i moved my cursor over it. When i tried to start it through clicking the desktop icon, nothing happened. Avast Cleanup still worked btw.
Yesterday, i deinstalled avast using Revo Uninstaller, as suggested by another help-site. After the uninstall-menu by avast, Revo asked me how strong it should look for leftover files, i chose "intense" (or something like that, my computer is in german). From then on, avast cleanup also stopped working, the UI popped up, but took extremely long to load.
Now when i run avast setup, i get an error "Der Prozedureinsprungpunkt "LOGONCLI.NetGetDCName" wurde in der DLL "NETAPI32.dll" nicht gefunden".

Malwarebytes didn't find anything, that's why i didn't post it to the virus section.

Thanks a lot in advance for any help!

[Pondus]

try running this, reboot then try reinstall  >>  https://support.avast.com/en-eu/article/Uninstall-Antivirus-Utility

[julipun]

Thank you for your quick answer, unfortunately, i get the very same error message when trying to start avastclear.exe: "Der Prozedureinsprungpunkt "LOGONCLI.NetGetDCName" wurde in der DLL "NETAPI32.dll" nicht gefunden".

[Pondus]

Contact avast  >>  https://support.avast.com/en-eu

[julipun]

Thank you for your time.