We would recommend that you use WD-40® Multi-Use Product on PVC or UPVC doors and windows. However, if the surface is painted we recommend that you patch test on an inconspicuous area first. We also advise you to contact the manufacturer of the door or windows to ensure using products on them doesn’t affect your warranty! Another product that would be suitable is WD-40 Specialist Silicone as it’s safe for use on rubber and plastics.