Hi,

I got the error once tried to use powershell. My OS: Windows Server 2008 R2 (64bit).

PS C:UsersAdministrator> Add-WindowsFeature NET-Framework-core, Web-Server, Web-Static-Content, Web-Default-Doc, Web-H
ttp-Errors, Web-Http-Redirect, Web-Asp-Net, Web-Asp-Net45, Web-Net-Ext, Web-Net-Ext45, Web-ISAPI-Ext, Web-ISAPI-Filter,
Web-Http-Logging, Web-Log-Libraries, Web-Http-Tracing, Web-Windows-Auth, Web-Client-Auth, Web-Filtering, Web-Stat-Compre
ssion, Web-Mgmt-Console, Web-Scripting-Tools
Add-WindowsFeature : Roles or features are currently being added or removed on this computer. Only one user can add or
remove roles or features at a time to prevent conflicting configurations.
At line:1 char:19
+ Add-WindowsFeature <<<< NET-Framework-core, Web-Server, Web-Static-Content, Web-Default-Doc, Web-Http-Errors, Web-Ht
tp-Redirect, Web-Asp-Net, Web-Asp-Net45, Web-Net-Ext, Web-Net-Ext45, Web-ISAPI-Ext, Web-ISAPI-Filter, Web-Http-Logging,
Web-Log-Libraries, Web-Http-Tracing, Web-Windows-Auth, Web-Client-Auth, Web-Filtering, Web-Stat-Compression, Web-Mgmt-
Console, Web-Scripting-Tools
+ CategoryInfo : OperationStopped: (:) [Add-WindowsFeature], Exception
+ FullyQualifiedErrorId : WizardLocked,Microsoft.Windows.ServerManager.Commands.AddWindowsFeatureCommand
PS C:UsersAdministrator>

Another thing: I following your Video. Do I need to install SQL Server? Before running installation?