Fixing window condensation on vinyl windows
Condensation appears to be on the inside of the window. 

After 10 years, the seals have failed. They are no longer "gas-filled" - they just have air in there, and the air in there has water in it, which condensed when they are cold. The only way to fix this is to replace the double-pane unit. It's remotely possible that if your window manufacturer was optimistic this MIGHT be a covered failure (they would pay for or supply the replacement panes under warranty), but it often is not.