How can I fix my upvc bedroom window which won't open?

The problem sounds like either the handle spindle which is easy to replace or the locking system which is more complicated. Check another window in the house and identify the lock, a name will be stamped on the face plate. Check the backset and how many roller cams or locking points it has. Measure the length of the lock ie the length of the face plate. It will be in metric. Search the internet to find a replacement and as suggested take the glass out, manipulate the locking points until open. Take out the handle and the locking system. Replace the lock and handle.

Paul
March 2011

can't think what could go bang, you will have to take out the glass & try to lift or shake it open.

Lee
March 2011