If so, download the EXACT same version (E.G. Home Premium x64 - 64 bit) from here and burn it to a blank DVD. Next, go to Acer support for your region, click on "Drivers & Manuals" and enter the model of your laptop. Download & save all drivers & applications to a external drive or burn them to another disk.
Boot from the Windows disk you made and install Windows. Use the product key that is on the base of your laptop. When finished, install the relevant drivers & applications, all your documents (from a previously made backup) and your Anti-Virus/malware and programs. You will also need to activate Windows. When done, you're good to go!
However, if it isn't Windows 7, you will need to purchase a new disk and install from that.
It’s time to recognize brummyfan2 for his dedication and collaboration. Please join us in welcoming brummyfan2 to our ACE Team! brummyfan2 has been a valued member of the Acer Community since 2013, eagerly helping users troubleshoot their products.