CPU constantly goes on 100% usage

OK, avguard.exe is an Avira program.
In post # 6 you stated:

I have disabled avg real time protection

That's why i asked...AVG and Avira are different anti-virus products...

I don't use Avira, but I found this older Avira support thread for a problem like yours.
You can look at this thread, and perhaps try suggested solutions...

Hi,

Maybe I wasn't clear in my previous posts for you:
Try to (separately):

1) Disable ProActiv and monitor the situation. If you still encounter the same problem, then
2) Completely reinstall Avira using Avira RegistryCleaner, if you still encounter the same problem, then
3) Try to disable the product protection in Configuration of Avira and monitor the situation.

Also, t will be good if you will be able to catch a process dumpfile of avguard.exe during the problem... and yes, you can use the latest version of WinDbg.

Source: avguard.exe has high CPU usage

Maybe Avira had a recent program update, maybe some other program update is causing a conflict, maybe you have malware, ...

Posting the screen print by CPU when you have a problem will help more than just typing in your "findings" as in post #6.
A picture is worth a thousand words...