“MYSQL dump and MYSQL path does NOT exist”

I just installed WP DB manager as a new plugin but when i want to go to “Backup DB”, the following messages appears:

Checking MYSQL Dump Path …
MYSQL dump path does NOT exist. Please check your mysqldump path under DB Options. If uncertain, contact your server administrator.

Checking MYSQL Path …
MYSQL path does NOT exist. Please check your mysql path under DB Options. If uncertain, contact your server administrator.

According to these messages, mysqldump and mysql does no longer exist :s

Where can i find mysqldump.exe and mysql in my database ?? Can i export them to my C:/ ?

Thanks for your help !