Hi, i have a upvc window that i cannot open, the widow is locked by a standard lock adjacent to the handle and upper and lower shot bolts. When operating the handle the lower shot bolt does not release itself from the locking plate. The window will open about 10mm at the top but the bottom remains secure. I am stuck as to what to do

G.Preston, January 2014

You need to deglaze it, you should then get enough lift to open.

Len, January 2014