I haven't played with tagging since I jumped right from XP to 7...so want to do the windows live thing.
But seriously? Nope..don't need ACDsee..save your $$![]()
If you wanted you could always use Picasa which is free. It still doesn't fix the PNG problem, but as Kristi said, that's a file format issue not a program issue. I've been converting all my PNG elements to PSD so the file tags are stored within the file. It's a pretty quick process and then I can have the same tags no matter where those files go, which is nice. I use PSE on my daughter's laptop and PSCS5 on my desktop. I can view the tags in Bridge, Lightroom, PSE, whatever. Love it.
Oh now this is an interesting idea!! I might have to experiment with that.
Also with Windows Photo Gallery I can tag *.png files. So I'm not sure what's going on if you aren't able to tag PNG files. Maybe there is an option somewhere in Photo Gallery??
I tag my .png's in WLPG. And I'm not sure how but they have transfered from computer to computer within my house/network. Although I noticed the other day it dropped some of the .png tags randomly. So it isn't 100%.
WLPG doesn't thumb preview .psd. So I usually save those as .tif files.
Leah, I wonder why it won't tag .png files in your version? Are they even loading? It sounds like something is corrupted.