Question: My end goal is that I want to wipe all of Ubuntu off my computer completely and run Windows 10 solely. Right now I have both of them on my system, but I am unable to get to the Windows 10 login screen because I'm greeted with "Error: Unknown filesystem" and enters me into grub rescue>. I'm not sure how to continue from here to the Windows 10 login screen, and how I can completely remove Ubuntu from my system.

Answer: 
Pipelight solution does not work at the moment, but Firefox with Flash on PlayOnLinux does.

1. Install and run PlayOnLinux

> 
> 
> ```
> sudo apt install playonlinux
> 
> playonlinux
> 
> ```
> 
> 

2. Click Install and search for Firefox

[![enter image description here](https://i.stack.imgur.com/dX5dl.png)](https://i.stack.imgur.com/dX5dl.png)

3. Select Flash when prompted
4. Run Firefox

[![enter image description here](https://i.stack.imgur.com/8sL6B.png)](https://i.stack.imgur.com/8sL6B.png)

5. Go to HBO website and if the videos still do not work, install the Flash they link to.
I believe you need to install the "hal" package (short for Hardware Abstraction Layer; it allows certain DRM-protected Flash content to verify what hardware device it's being played on, to prevent piracy)

Open a terminal (Alt-Ctrl-T) and add Martin Wimpress's HAL PPA (he's the developer behind Ubuntu MATE):

```
sudo add-apt-repository ppa:flexiondotorg/hal-flash

```

Then update your package listing:

```
sudo apt update

```

and install hal:

```
sudo apt install libhal1-flash

```

Then, to make sure Flash is aware of the changes:

```
cd ~/.adobe/Flash_Player

rm -rf NativeCache AssetCache APSPrivateData2

```

Adobe does provide an online test to see if DRM in your player is working. The URL is <http://drmtest2.adobe.com:8080/SVP/SampleVideoPlayer_FP.html> , and you can test it by entering the following URL into the "video URL" box on that page: <http://drmtest2.adobe.com:8080/Content/anonymous.f4v>

Please let me know if this was helpful, or if you ran into any issues!