UPDATE 8/3: Apparently in Windows 8/8.1, Acer and other vendors use a tool called "WIMBOOT" which uses files stored in the recovery partition to boot your main system (although, surely your machine doesn't require 10gb of data to start up every time). The solution? Upgrade to Windows 10, and "Back up system files" as described below.
DISCLAIMER: BACK UP YOUR DATA FIRST. The following directions may result in irreversible filesystem corruption, particularly if you make a typo. I recommend using any commercial or free drive imaging software prior to following these instructions, and offer no support or warranty if disaster strikes.
Microsoft's documentation seems to indicate that it is possible to delete the recovery partition from your PC as an option when creating a USB recovery disk. However, this did not work on my machine. Fortunately, there is a solution; however, it involves a few "advanced" steps that include using a command-line tool called diskpart:
- Obtain a > 4GB USB drive
Windows needs just under 4 GB to create a recovery drive for your machine. Technically, this step isn't required if you allowed your PC to automatically upgrade from Windows 7 / 8 to Windows 10 as you can use Microsoft's Media Creation Tool.
- Create a recovery drive
Use the media creation tool above, or (even easier) type "Create a recovery drive" in the Start menu's search box. Make sure you choose "Back up system files" in Windows 10 when creating your recovery media.
- Boot from the recovery drive:
- Type "Change advanced startup options" in the Start menu search area
- Under "Advanced startup," press the "Restart Now" button.
- Click the "Use a device" icon
- Select the option that corresponds to the removable device that you made into a recovery drive to boot
- Obtain a command line and launch diskpart:
- Choose your keyboard layout
- Under "Choose an option," select "Troubleshoot"
- Under "Troubleshoot," choose "Advanced options"
- Under "Advanced options," choose "Command Prompt." A big black box appears.
- Type diskpart and hit enter.
NOTE: The following directions assume that the "Rescue" and "Primary" partitions are next to each other; i.e. Rescue is Partition 4, and Primary is Partition 3. If this is not the case, you should STOP HERE and use something like Partition Magic or gparted to do the job.
- Delete the recovery partition
- type: list disk
- The resulting list will probably have your system's disk as "Disk 0." Look at the Size column to figure out if it corresponds to the size of your internal drive.
- type: select disk x, where X is the disk # of your system's internal drive.
- type: list partition. Look at the "Type" column for a "Rescue" partition (the size should be ~ 10 GB).
- type: select partition x, where X is the partition # of your system's rescue partition.
- WARNING: the following step will delete the partition. Double-check your work.
type: delete partition
- Resize the "primary" (system) partition and filesystem
- Consult the results from list partition and type: select partition y, where Y is the partition # that corresponds to the "Primary" system partition (it should be the biggest partition, by size).
- type: extend
- type: extend filesystem
- type: exit and hit enter, then type exit again. The command prompt window should close.
- type: list partition. You should see that your "Primary" partition is now much bigger. Hooray!
- Reboot into Windows
- Under "Choose an Option," click Continue (boot into Windows)