MUSHY/BLURRY GRAPHICS in PowerPoint
PowerPoint antialiases all raster images.
Translation from GraphicsGeekSpeak: It blurs the edges of GIF, JPG, TIF and other bitmap files to minimize the jaggies.
Normally, this improves the appearance of your images, but for some types of images (screen shots especially) it produces nasty, mushy-looking results.
Unfortunately, there's no way to turn off this feature (and it generally IS quite a nice feature).
For screenshow use, there's a trick.
Start with a blank presentation and insert your raster image.
Size it to fill the slide without distorting it.
Choose File, Save As, and pick Windows Metafile (WMF) from the Save as Type dropdown list box.
Give the file a name and save.
Now insert the WMF into your real presentation instead of the original raster image file.
Dig it: No antialiasing.
This dodge seems to work fine for screen shows, but be wary of using it in files you need to print or send to a service bureau for 35mm slides or other output.
It may not print well.
Or at all. It doesn't work at all on my PostScript printers.
Bring your bitmap image into into a bitmap editor. Humble MS Paint works fine for this, by the way.
Select the portion of the image you're after and choose Edit, Copy to put it on the clipboard.
Switch to PowerPoint and choose Edit, Paste Special. Pick Enhanced Metafile from the list and click OK.
PowerPoint leaves the pasted image alone; it doesn't anti-alias it.
One possible drawback: This will probably bump up the size of your PPT files far more than if you simply added the original image, since PowerPoint may not compress the pasted image.