If your hard drive is corrupted or physically broken, you will need a copy of the version of Windows that came with your machine. Any OEM copy should work because the license (key code) is in non-volitile memory.
If Acer still has the recovery disk for your model, they probably won't charge you more than ~ $25 for it so it may be worth it to get it. The Windows license is built into your laptop so you're not buying a new Windows license, just installation media for the license you already own.
If you want to do it manually, and have the model number of your laptop:
1. Search Acer's site for the drivers and utilities for your model, and download them, there. If they don't have all of them, search Google for your model number + drivers. Be careful to use reputable download sites to avoid malware.
2. Do your base Windows installation. Don't worry about activating it until you've installed your drivers because you won't be able to get online until you have a network connection. In fact, don't go online, at all, until you have installed your anti-virus, anti-spyware and any other security software you use.
3. Create a sub-folder in your Downloads folder, and copy all of the drivers you need to it. Then, you can conveniently install them from that folder.
That should get you to the point where your ready to go online, activate Windows and settle in for a long session of Windows updates.
Hope that helps. Good luck.
