Welcome to the forum.
It appears that there is a DDS plug-in for nVidia video cards for Adobe Photoshop CS5 Extended. Which video card do you have? I do not know this site, so cannot vouch for it. If you have the right nVidia video card, and PS Extended, scan any download carefully, before installing: http://paulus1ittechician.blogspot.com/2011/02/dds-plugin-for-photoshop-with-nvidia.html
I am unsure of which version of PS you have, and wonder, as does MTSTUNER, whether you mean Photoshop Elements 9 (totally different program, than PS, or PS Extended, which is at version 9).
These plugins from Nvidia should work in pse9 (download the 32 bit version)
with some limitations, so read the included pdf files.
The only part you might have trouble with is using the installer and since the machine
i have with pse 9 also has a version of photoshop, i can't tell you whether the installer
will work or not.
Perfect...I did download the 32 bit version and installed it to the plugin file under the program files. The installer removed a previous version of Navidia plugins and there was a dialog confirming that I wanted to keep the new file. I think I did alright as I was able to access and save the dds file. Everything seems to be working just fine. Thanks for your help