Unable to Install .NET Framework 3.5 from Exchange Server 2010 Remote Management Tools installation:
Capture-ExchangeInstallError

Run from PowerShell: (replace F:\ with the DVD drive where your Windows media is located)

Dism /online /enable-feature /featurename:NetFx3 /All /Source:F:\sources\sxs /LimitAccess

Capture-ExchangeInstallNET35