The passenger side window in my 2007 Nissan Dualis has come off its track

This can be a bit of a fiddly job and requires you to disassemble the inner door trim to get at the workings within. The problem itself is usually a case of either the glass having delaminated form the metal track it rides it, or the winding mechanism itself has broken or rusted through or structurally failed in some other way.

Once you’ve removed the inner door panel and any protective sheeting under it, you should be able to see what’s failed or fallen off. You’ll need a good torch and perhaps even a mirror to see what’s going on in there as access can be tight.

If it’s a simple case of the glass having jumped out of its metal track, you may be able to refasten it with the correct adhesive. Often, though, it’s simpler and easier to find a replacement glass and track unit at a parts recycler (which we used to call a wrecking yard). If something else has failed, you may need to replace a whole lot more in terms of components, but until you can see what’s what, you won’t know for sure.

The other advice is to not try to move the window via the power window switch. Depending on where the glass is sitting, you may find the winding mechanism will bear on the glass where it shouldn’t and smash the pane or bend something important.