First of all, your problem isn't caused by anything in the BIOS. You cannot fix that error by doing anything in the BIOS because it's an operating system error that occurs as the system is booting up, usually as a result of an incorrect install, such as not formatting the disc prior to the install, leaving two system partitions on the machine and leaving the OS pointing to the original boot partition (partition 0) instead of the the new boot partition (partition 1)
Going into the BIOS will not recover a missing file, and there is no "reset" utility in the BIOS. The BIOS contains the basic configuration settings the very first part of the bootup program looks at to know where to look for the hard drive,the memory, the monitor, the keyboard, the mouse, etc. Resetting the BIOS does not reset the operating system. It will change all of your settings for the BIOS (your memory timings, your fast boot up, whether your computer recognizes new flashdrives plugged into it, and so on). It will not fix a missing file in the operating system, and could render your system very slow and unresponsive. You should not reset the BIOS if you are not familiar with the various items in the BIOS and able to correct any problems that a unnecessary reset may cause. Do not reset the BiOS to correct a missing file, or error message that occurs during boot up, or the failure of the OS to boot after performing a fresh install of the OS.
There are other steps to take that are more appropriate, dealing with accessing the hard drive, restoring and repairing the Operating System and repairing or replacing any corrupt or missing files, which is actually the cause of your problem. Even a complete resinstall, done correctly, formatting the entire hard drive at the very beginning of the install and letting the installation program correctly create the partitions it needs and placing brand new pointers on the disc to where everything is actually located is more appropriate than resetting the BIOS, as the BIOS has nothing to do with the machine not finding the files it needs to boot properly, which your error message is telling you is the problem it's having. It's not having a problem with the BIOS... at all.
Having said that, here are the instructions on how to get into the BIOS on an ACER machine when don't have the password on a password protected machine (simply because that's what you asked for, not because you should go in there an do anything, especially if you are not familiar with all the settings in the BIOS of your computer) -
How to Reset an Acer BIOS Password
Now, to actually start taking steps to fix your computer -
The first thing you can try is the System Repair Tool that's included on the installation disc. (Of course, I'm assuming you have a genuine Windows 7 installation disc, and not some modified system restore disc that Acer provided.)
Here's how to perform a System Repair using the instillation disc -
How to Automatically Repair Windows 7 Problems
If that doesn't resolve the problem, you can try running the System File Checker utility using the Repair Tool, as well. Here's how to do that -
Run System File Checker in Safe Mode Boot Time or Offline
If none of those processes work to restore any missing files, or repair any problems with the registry pointing to the wrong location of where the files it needs to successfully boot to the desktop and to begin running properly, rather than go through a half dozen additional explanations of more processes, or teaching you about the tools and utilities a computer professional might use that would allow him to look at your drive partitioning, look inside and view your directories and see what's going on internally, it will take far less time, perhaps 45 minutes or so to simply format your drive and perform another install, doing it properly this time including a full format of the drive before anything else, (What's referred to as a "Clean Install").. Here's how -
How to Reinstall Windows 7 From Scratch
any one of these will get you up and running again...
(IComputer Professional for 30 years)