* Save your files in PC 8.3 filename style, using PPT (for PowerPoint presentations) or PPS (for PowerPoint shows) as the extension ... the part after the period. Your filenames should look like XXXXXXXX.PPT or YYYYYYYY.PPS

* Uppercase/lowercase doesn't matter, but don't use punctuation characters or spaces in your filenames. Some punctuation marks are PC-safe but may cause problems in email or web applications if files are converted. Dashes (-) and underscores (_) are safe, though.

* Quicktime-compressed images won't work on the PC. Don't copy/paste images into PowerPoint. Use Insert, Picture, From File instead. Use JPG or PNG formats for images.

* Quictime movies seldom work on PCs. Use MPEG or AVI instead.

* Links to external graphics files will break. Embed all graphics.

* Links to most media files will break UNLESS you copy the media file to the folder where the PowerPoint file is, and only then insert it. See Links break when I move presentation for more information.

* Check Format, Replace Fonts to see what fonts are used in your presentation. You can safely count on Arial, Times New Roman, Courier and Symbol being present on every PC. Tahoma and Verdana will probably be present on any PC with Office 97 or later, but may not be there if the PC has only the free PowerPoint Viewer. Remember, Mac versions of PowerPoint can't embed fonts or use embedded fonts.

* Use only RGB color for your PowerPoint graphics. PowerPoint will convert CMYK or Pantone colors to RGB anyway. It's better to do it yourself so you can control the conversion. In case that's not a convincing argument, try this: PowerPoint may substitute a red X for CMYK graphics. Ouch. Stick with RGB.

* Ungroup, then regroup imported graphics to convert them to PowerPoint shapes. Do the same to inserted charts if you don't need them to be editable on the other platform.

* Don't squeeze your text too tightly into placeholders. Font substitution and slight differences in text rendering on Mac vs PC can cause your text to get truncated or spill out of too-tight text boxes.