Things You'll Need
If you want to install blinds to the encasements on your Andersen windows, understand that the manufacturer uses hardwood lumber constructing the windows. For this reason, it's necessary to ensure you that can mount the blinds' hardware to the encasement without stripping out the screws that come with the hardware.
Position the left retaining bracket in the upper left hand corner of the window encasement and mark the holes in the retaining bracket onto the encasement with a pencil. Repeat the process with the right-side retaining bracket.
Drill pilot holes through the marks on the encasement approximately 1 inch deep with a drill bit that measures half the diameter of the screws supplied with the blinds. The screws are made of relatively soft metal. They will strip easily if you do not drill pilot holes.
Place the left bracket over the holes drilled into the left corner of the encasement and secure it with the supplied screws and a screwdriver. Repeat the process with the right-side bracket.
Attach the headrail to the brackets. This procedure will differ depending on the brand of blind you use. In some cases, you insert the top of the brackets into slots on the top of the headrail and then press the bottom of the headrail into the bracket. In other cases, you place the headrail into the brackets and slide covers onto the brackets to hold the headrail in place.