You don't actually need Powerpoint to read .pps files.
Microsoft offers a free viewer at
http://www.microsoft.com/downloads/d...DisplayLang=en
As Keef suggests, the version is relevant. This one will read Powerpoint 97 thru to 2003 (which should cover most). For the new '2007 format, there is a converter listed at the bottom of the above page.
Snooze
(can't help with the others
)