XnView is a handy image browser I've come across which supports the DDS format, I've been using it a lost when working with particles for skills.
XnView is an efficient multimedia viewer, browser and converter.
Really simple to use! Support of more than
500 image formats
.
No Adware, No Spyware
Irfanview is another image program that opens .DDS images out-of-the-box.
Not a full-blown editor, but can do some simple editing like change compressions and resample resolution...
www.irfanview.com/