Export EPS from PowerPoint

You can't export EPS from PowerPoint, but ...

If you have Adobe Acrobat That's Acrobat, the full package, not just the free Reader. If that's what you've got, you've got it made.
Make a PDF from your PowerPoint presentation, open the PDF in Acrobat, then export the page you want to EPS, choosing the preview image, PS level and font embedding options you'd like.

If you don't have AcrobatSome PostScript drivers allow you to choose EPS as the output format. Whether your driver supports this will depend on the driver and the version of Windows you use.

First, set up a PostScript driver (install one if needed) You'll want the most generic color PS driver you can find; some drivers may include device-specific PostScript even when they're producing EPS.
Open the printer driver properties page and do the following:
On the Paper tab, choose the same size paper as your app will be set to.
If available, click Unprintable Area and set all the unprintable margins to 0. Otherwise you'll get unexpected white borders around your EPS.
Some apps will automatically adjust orientation when you print, others will not. You may need to set the Landscape/Portrait orientation properly. If in doubt, set it here.
On the PostScript tab, choose Encapsulated PostScript (EPS) in the listbox called PostScript output format.
Accept these changes.

Then start PowerPoint.
Open the file you want to export to EPS.
Verify that your document page settings and the driver page settings match.
Print. In the print dialog, check that the following options are set:
Print Current Slide only, or a 1-page range of pages. An EPS file with more than one page image is an abomination, and WinMom won't let you do it. Don't try.
Likewise, make sure number of Copies is set to 1
Put a checkmark next to Scale to fit paper (you don't want white borders around the EPS)
Put a checkmark next to Print to file (since a file is what you're after here ... the driver will natter at you and give you an opportunity to change this if you forget, however)
OK the print dialog. You'll get a File Save dialog box. Give your file a name. WinMom may decide she knows best and append ".prn" to whatever you type here; if so, rename the file in Explorer. If you type the entire name in quotes, she'll leave it alone.

Did it work?
Import your new EPS file into any app that supports placing EPS and see the results on screen in ... um ... glorious living grey rectangle. The driver doesn't create a preview image for the EPS, just the PostScript part. This is perfectly valid and should print fine to a PostScript printer, but it's a little unnerving if you expected to like SEE something when you imported the file.
And to a non-PostScript printer? You get the grey rectangle. Again, this is normal. Not what you might want, perhaps, but normal. Don't use EPS graphics if you're not printing to PostScript printers.

http://www.pptfaq.com/FAQ00045.htm