New Leded Windows

one of my custmers has had new windows put in they were clean when instald but that nte it rained an the lead left runs all over the glass i tried scrubin it wfp tried to different brushes then went up ladder got some of it off but not all,is there a chemical that will get it off does any one no????

I've used Virosol before. It shifts the bleeding that runs out of the lead. Use the Virosol on an old cloth, rub the stains off, mop up window, blade excess water off, buff with microfibre. It works, but it's long winded.