mysqldump access denied

I think that you would have to lose the = when using -p or do it with --password :

--password[=password], -p[password]

The password to use when connecting to the server. If you use the short option form (-p), you cannot have a space between the option and the password. If you omit the password value following the --password or -p option on the command line, you are prompted for one. Specifying a password on the command line should be considered insecure. See Section 6.6, "Keeping Your Password Secure".

You have to run CMD.EXE as the Administrator:

Right click on cmd.exe --> Run as Administrator and then type your command:

mysqldump -u[username] -p[password] -h[ip or name] yourdatabasename > c:\sqlfile.sql

It should work fine.