"Zij heeft het raam geopend."
Translation:She has opened the window.
The e is there, but as it's in an unstressed syllable it's pronounced as a schwa (the sound of the 'e' in the English word 'open' (which can be transcribed as /ˈəupən/), so it's kind of imperceptible. Kind of, because it definitely doesn't sound the same as saying 'gopend' (at least, not to my ears).
It depends a bit how picky you want to be. Raam usually means the window (glass including frame), so that's the thing you open (however people may use raam referring to the glass only). Ruit is just the glass of a window. So in the first sentence below, ruit normally isn't used, for the others it doesn't really matter which one you use:
- ik open het raam
- ik kijk door het raam/de ruit
- het raam/de ruit is beslagen
- de bal vernielde het raam/de ruit