Hello, not sure how old this acer machine is but if it an old one then it probably would have have come with a recovery cd in the box.
Some old xp acer machines you could boot into windows and load up the eRecovery Utility by pressing alt + f10 and in that program you would have the option to burn your own recovery disks or to start a recovery etc. If it as you for a password then the default was 000000.
You can also normally load the eRecovery utility on boot up by holding down alt and pressing f10 as soon as the machine is turned on. This is the case for new acers and some old ones with out recovery disks supplied
If it is a newer acer with vista then boot into vista and look for a program called Acer eRecovery Management and again that has all the options to burn disks and recover the machine.
That all my limited knowledge of acer recoveries streches to so i hope it helps.