Many Thanks All, for the feedback, like i say it was the worst first clean i have ever done, and i only took it on because it was next to my other work. I dont think it was a over spray or anything, as i would of felt it with the blade, but just a very aged, and a never cleaned glass thing. I do THINK that the windows i mention are knackered, and can't be put right without some sort of serious acidic cleaner for the glass or a rubbing compound? and that's the MAIN reason i asked the question tbh, because i didn't want the customer to get a second opinion off another windy, and for him to pull out some sort of miracle spray to get it clear, which wouldn't look good on me, especially as it was a recommendation. I now feel better knowing the above feedback. Thanks again. M