Here an 3/4" Fogged Insulated Unit was taken out and replaced with a new 1" Insulated Unit in the original opening. Fogged Insulated Units have moisture inbetwen the two panes of glass and there is no way to clear the condensation or stains up unless a new unit is installed.
This picture illustrates the make-up of an Insulated unit and how it shows that there are two seperate panes of glass with a thermal band inbetween. When being fabricated the Insulated Unit is Vaccumm Sealed to eliminate any Moisture.
These are three Wood Double Hung Pella Windows that are designed with energy efficient glazing. Wood windows are usually installed unfinished and to be painted or stained after installation to avoid additional costs.