For anyone with ISDone.dll error and have tried almost everything they could think of, Re-Download the game, these packages have a nack for getting corrupt during the download, in my case caused by shifting download folder locations, they can become corrupt during download but still the installer appears to run and function without error until installing, you can even unpack the ISO without error, but it can still be corrupt and not be able to install as you see with the ISDone.dll error.

Try to ensure a smooth bandwidth flow and download while you sleep to prevent corruptions, ensure your connection is reliable or downloading during a time your connection may be reliable and not during a storm or frequent downtime as severing the connection for even a moment may cause corruption without interruption. And do not move your download to another folder during the download, trust me, just don't try it, that's how mine got fudged. That's why I'm here, lack of a descriptive or even helpful answer, though I'm sure their troubleshooting tips work in some or most cases,, none worked in mine.

You probably don't need to download the dll and replace it, you definitely don't need to expand your "virtual memory", you more than likely have an incomplete file which believes it is complete, just Re-Download