Problems with MySQL Table ‘.\mysql\db’

Been having problems with MySQL, it wont launch at all, i just get error messages

Ive tried changing ports and deleting files etc. Nothing i try has worked at all Logs look normal but when i look at windows event viewer i get the following three messages

"mysqld.exe: Table ‘.\mysql\db’ is marked as crashed and last (automatic?) repair failed "

"Fatal error: Can’t open and lock privilege tables: Table ‘.\mysql\db’ is marked as crashed and last (automatic?) repair failed " "Aborting "

How would i fix this issue? All help is appreciated