Problems going from Keynote->Powerpoint

[CorvusCamenarum]

A friend of mine needs help. She just bought an iMac (hooray), and is trying to make presentations in Keynote for use in Powerpoint on a PC where she works. Normal exporting does not work; when she tries to call up the file on the PC, it says it can't open the file because of a missing text converter. How do we fix this? Thanks in advance.

 

[Allimuse]

The friend...

So I'm "the friend" mentioned above. I downloaded a ppt file. I worked on it in Keynote and then exported it as ppt file. I emailed it to myself and opened it on a Microsoft 2007 version of ppt. It opened, but none of the work I did in Keynote was there. It was the original file. When I opened the same email and downloaded the file on a mac with keynote, it was all there. Problem: I have to use a PC at the school that has Microsoft 2007 ppt. Any ideas? The presentations are the critical reason I bought a new computer. Please help...