HiCan anyone suggest a product that will remove the above from internal windows? I have a job coming up which is pretty dirty! Cement/putty and paint all over the windows. I suppose it'd be considered a builders clean but it's from a customer who's brought the house next to his which was unfinished. Any help appreciated.[/quotetry some u.p.v.c frame cleaner its what the window fitters use it should workhere's the link for you to look at http://www.cglass.co.uk/everbuild-pvcu-solvent-cleaner-pr-16749.html