Here are the instructions - do this on your laptop:
First, go to this webpage:
It describes how to create a Windows 8.1 installation media. Click on the Create Media button and run the downloaded tool. Select the language, edition and architecture. Make sure to match the one that is installed on your Acer computer.
Click Next and you can choose between creating a bootable USB flash drive or a bootable disk (ISO file). In case you have an USB flash drive, you can plug it in and use it for creating a bootable Windows 8.1 media. Note that the process will format the USB flash drive, so make sure to transfer the important files to your laptop first.
If you want to create a bootable disk instead, select the ISO file option and click Next. You will be prompted where to save the file, and then wait until it has been downloaded from the Internet. It may take some time. When done, you can burn the ISO file onto a blank DVD (not CD). To do that, you can use a free program named Free ISO Burner which you can download on this link:
Start Free ISO Burner and insert a blank DVD. Click Open and locate the ISO file you downloaded using the media creation tool and then click Burn. After you have burned the disk, eject it and insert it into your Acer computer. Restart the computer and the computer should then start the Windows 8.1 setup.
You may need to access the BIOS on your Acer computer and set booting from either an USB flash disk or DVD, depending on what you chose to create.
Once your Acer computer has booted from the Windows 8.1 media, you will see the Windows Setup window with two options:
1. Install Now
2. Repair your computer
Click on "Repair your computer". The "Choose an option" screen will appear. On that screen, click on "Troubleshoot", and then click on "Advanced options". First, select "Automatic Repair" which should automatically detect and fix all found boot problems. The computer will restart and let it boot to Windows 8.1 as usual. In case the problem remained, boot from the Windows 8.1 installation media again, and follow the same steps, but this time select "System Restore" instead.
On the System Restore window, select a date you know your Acer computer worked just fine. The process will attempt to restore all Windows and program settings to that date, so hopefully, this will solve the problem.
Let me know the results.