i have a ~ 45000k sql generated from mysql. I opened the sql file using notepad but it's all scramble. this is very old back up and i dont have access to the db anymore. can anyone please tell me if need to use mysql tool to execute the sql file.

Have you tried opening with wordpad?
Notepad expects a dos formatted file and I suspect it's more unix based.
You should be able to pass it straight through MySQL.

Mike