Windows help needed but not for PC

On mine there is a curve-shaped moulding at the top of the window, and that fits into a slot on the outside of the ridge.
You hold the window out at a 90' angle and slide it along the ridge til it's in the right place.

It then just pivots inside the slot on ridge bar..............I hope that makes sense 

It doesn't sound a lot different from the arrangement on my ally/glass greenhouse - there is nothing to stop the window from sliding along the curved moulding it is fitted to, so it had to be opened straight upwards with a little care, or it wouldn't go back into its proper "seating" when closed again.

(Problem was solved by fitting an automatic vent opener which has a truer "aim" than I have!)

I spent three years at college learning all about "Technical Comunication Techniques"  and the "Transfer of Technical Information" qualifying to City and Guilds level.  Because I saw how slipshod and downright unfathomable were the 'technical instructions' that came with the average products.

After I had qualified, I then found out that most companies just grabbed someone from the reasearch and design department and  told them to 'get on with it'.  When their thoughts were already on the next product.

I did help in comiling Health and Safety Instructions and Statutory Instructions for 'buckets of sunshine' and found it extremely interesting and rewarding.    Cheers,     Tony.