Opening .ppsx in PowerPoint 2000

I am trying to open a presentation saved as a .ppsx file using my installed Microsoft Office 2000 PowerPoint.
If I just double click on the file it opens in PowerPoint viewer but I can't edit it there. When I try to open it in PP 2000 I get the message "Power Point can't read the outline. No text converter is installed for this type of file".
I have downloaded several "converters" from the WWW but none seem to work.

Help please. Thiks is an important presentation that I have to make shortly but it needs additional stuff adding to it.

I'm not a powerpoint expert and I'm really not that well versed in Microsoft Office, either. But I think you're going to be severely limited in what your Microsoft Office 2000 will be able to do. Microsoft offers a free powerpoint viewer but it doesn't have any editing capability.

Download PowerPoint Viewer from Official Microsoft Download Center

You may want to consider using either OpenOffice or LibreOffice (both free office suites that are probably 90-95% compatible with Microsoft Office.)

Apache OpenOffice Product Description

Features » LibreOffice

Many thanks marsmimar. Yes I've heard of these so will give them a go. Once I've done the editing I should be able to save the file in a readable format! Come to think of it, I believe there is a Power Point on our iMac so that may also be a solutions.

Cheers

OK, further to my last, I found a Power Point on the iMAC and it imported the .ppxs without any problem. I then saved it back to the mem stick as a .pps file and now I can open and edit no problem in my old 2000 Power Point.

Thanks again. Next time I'll work it out a bit more before posting it as a problem!

Excellent solution! Thanks for posting back.