Protect a Power Point from changes:

Many people need to protect PowerPoint files from changes. There are many reasons for this:
To send presentations for review only (but not editing)
To maintain ownership of the creative content
For legal reasons (for example, if the content has been approved by legal and financial counsel and may not be changed)
To provide presentations for others to deliver but not modify
You can choose from a number of techniques, depending on your situation. One of the easy methods for creating static slides is given below.
Convert to images
If you don't have animation, you can convert the entire presentation to images, so that each slide contains an image of the original slide. Of course, people could still remove slides or images, but this method is easy and is often used for review and maintaining creative ownership. It also allows you to protect some slides and not others. This is useful if you want to allow people to change some of the slides. Follow these steps:
Choose File> Save As. (In 2007, Office button> Save As.)
In the Save As dialog box, click the Save as Type drop-down box and choose the JPG or PNG option. You can change the file name if you want or keep the default name.
Click Save.
At the dialog box asking if you want to export every slide or the current slide, click Every Slide.
Click OK at the dialog box that tells you were the image files were saved. PowerPoint creates a subfolder for them.
Create a new presentation. You now need to insert the images, and there's a shortcut, the Photo Album feature. Choose Insert> Picture> New Photo Album. (In 2007, choose Insert tab> Illustrations group> Photo Album drop-down arrow> New Photo Album.)
In the Photo Album dialog box, click the File/Disk button. Choose the images you created earlier and click Open. (You can press Shift and click the first, then the last image you saved earlier to select them all.)
You'll return to the Photo Album dialog box. In the Album Layout section, choose the Picture Layout you want. Usually, you'll choose Fit to Slide or 1 Picture. Click Create.
PowerPoint inserts one image on each slide and creates a title slide, which you can then delete. Save the presentation.