Hello, I am moving this up one forum to Am I Infected
avgnt.exe is a Windows process part of Avira Internet Security Suite. With the other symptoms you have a Rogue Application infection..
Please follow our Removal Guide here Remove System Tool and SystemTool
You will move to the Automated Removal Instructions
After you completed that, post your scan log here,let me know how things are.
The log is automatically saved and can be viewed by clicking the Logs
tab in MBAM.
Copy and paste the contents of that report in your next reply. Be sure to post the complete log to include the top portion which shows MBAM's database version and your operating system.