|The default password set at the factory is 000000 (that's six zeros).|
(Unless the password has been changed by you or someone else).
"i have no disc"
You don't get a disc for pre-installed versions of Windows Vista, but you don't need one to run eRecovery during the boot process. You just need to know what key to press when you turn it on, to start the eRecovery program.
It will restore the factory default installation from a hidden partition on the hard drive.
Start your Aspire and hold down ALT & F10 at the same time when the Acer splash-screen appears.