Cant sign in to some web sites

When I try to sign in to some web sites my user name and passwords wont take, I am just trying to inquire if this is caused by AVG I just got this protection a few months ago so I am oblivious

Hello Debra,
Thank you for reaching us with your concerns. May I know if the issue is resolved when AVG protection is disabled? Right click on AVG system tray icon and toggle the On/Off slider to disable AVG protection.
Best regards,
Alok.