Couple OF Questions Re. Fitting New UPVC Wondow Units

I'm fitting a small, standard casement type upvc window unit in a bedroom. When you toe and heel the side hinged window, is it best to do it with the window closed or open?

Also, is it vital that the beads go in the same positions they were when the unit arrived from manufacturers? My brother was helping and took the beads out without noting positions. Just wondered if it's going to make a difference to refitting them.

Many thanks.

Just remembered another question. On Youtube videos about bead fitting, they advise fitting the short beads first, then the long besds, bowing them out a bit to slot the corners into the mitre of the already fitted short beads.

What if the short beads, which should be fitted first, are also the vertical beads? This conflicts with other advice about fitting the horizontal beads first.

Should I fit the short beads first, or the horizontal beads?

Best doing it with the window closed, Heal and toe as tight as you can then open the handle and using the handle lift the sash a little to allow you to get a small extra 1-2mm packer in.

As for the beads yes it can matter where they came from as there can be a variance of upto 6mm on every weld, You can just hold each one in place to see if they look the right size first.

As for the order it doesn't matter if they are vertical or horizontal 1st (except if the beads are scribed instead of cut at 45 degree angle)
The reason you generally fit the longer beads last is they will have more flex so its just easier that way.