Windows 7 - Powerpoint - How do I check how long is my presentation?

I have just created a presentation and I'd like to know how long is it to add some music and to know where should I fate the song out.

Thank's ahead

Play it and time it?

There are a few tips about adding music to your presentation, here:
How to add music to PowerPoint

Hi there
In addition to the answer above you might be interest also on adding sounds to EXCEL such as using Sounds for Input data validation

Not quite as easy but still doable here's a decent link to start with

Conditionally Playing an Audio File (Microsoft Excel)

cheers
jimbo

The music is OK but I want to know how long exacly is the presentation without timeing it!!!!

It'll be as long as you make it with the transition settings. Go to Slide Sorter view, if you've already got transition settings on it, then you'll see the time for each slide in slide sorter view.

If you're not setting it to automatically go from slide to slide (and you're using mouse-clicks to move to each slide), then you'll need to rehearse timing so it fits into your budgeted time frame.