Most forum sites will take a .pdf file so if the HAMB does then you just print the ppt as a pdf and then post. If you don't have the ability to print to pdf there are several freeware sites. I use this one: http://www.dopdf.com/
Another way - if your power point is just one slide then click and drag over the entire contents of the slide and then right click on any of the highlighted object and select save as picture, then choose the format (.jpg being a good choice). Then post the saved picture. The only drawback is any region on your slide that is between object will show up as black on the saved picture image. I fix that by placing a large white background object behind all the others on the slide and then saving as a pic.
Depending on what version of PowerPoint you have you can save the slides to a .PDF format. You can then convert the PDFs to jpg and post. It makes them easier to see as you don't have to download to view. If you have a more recent version you can save directly to jpg and post that way.