Installation Error: #1618

Error 1618 is a Windows error that happens when another program is already in the process of being installed. You should be able to resolve this issue by doing the following:

1. Press CTRL, ALT and DEL keys simultaneously
2. Click on Task Manager
3. Locate the process MSIEXEC.exe
4. Click End Process

You should be able to install Sync thereafter. Alternatively, restarting your computer should have the same result.