Thanks Martin - good to hear.
I am in Paris : see attached screenshot.
PS later - the avast! Account window is now back in English, but the advertisement on the Summary page still in Russian.
Your problem may be that the ORIGINAL owner of the IP subset you are assigned is Russian. My ISP is not always correctly identified when using various tools on the web (mainly speedtests), as my IP (example: 255.255.110.98) is owned by my ISP, but the etnire subset (example: 255.255.0.0) is identified as being owned by another company; the company who owns the Fiber Optic roll-out in my city).
I was worried at first until I called my ISP and found out thats what and why this was happening. I was worried because Im trying to prove Comcast DOES NOT have the fastest internet in the US, but my IP was listeing the first company on the WHO IS report. If your on a router, try cloning/changing your MAC address and see if that changes things. Also, call do a "WHO" IS ARIN report and see all the names that might be attached. This is how I found that my ISP was using IP's in a subset owned by a different company.
***If your WHO IS report reflects as such, I dont know for sure, but you may have to clean your installation and re-install to get correct language listing once getting a wholly owned ISP IP subset. Again, may not be neccessary as Im not sure how this language check relates to IP assingment and if it changes becuase IP is changed.***