My pc suddendly changed its default browser it was like a macro clicking in to the settings then changing it manually that i saw it on the screen? does this mean my pc has a virus that can control my pc
Probably not a virus... yet. Depending on how long it has been since you did this, and allowed the Malware to invite other infections. Download malwarebytes antiwalware (preferably from another computer). Install and run on the infected machine and see if that cleans things up.