The remedies to fix the condensation between the windows are: 1. Clean the Window Identifying the issue and correction at the right time avoid further deterioration of the windows. Clean the windows as soon as condensation is observed. 2. Replace the Window Panes If condensation has extensively penetrated into the panes that it cannot recover just by cleaning, then the panes must be replaced. This replacement depends on the type, age, and manufacture of the window. 3. Replace the window In a situation where glass cannot replace, the whole window unit must be replaced. If the windows are old, a replacement is a good choice.