*Update:  Pictures to come.*
*Update: wtf WPG?  You open pictures but you won't let me see the gallery anymore?  What happened?  I thought we were friends.  Don't make me uninstall you.*

If you've got a picture that looks like it would be ok if it weren't for the lighting, and you're willing to put some time into saving it, you might be able to salvage it.

For instance, i think I was able to dramatically improve the appearance of a photo of my dog.
Here's what the original picture looked like:

I played around w/ the contrast:

And the brightness:

Neither of which looked all that great, but when you combine the two:

And repeat:

It looks pretty good, I think.

The autofix feature didn't do diddley.

Some other things to note about windows photo gallery.
It automatically saves the changes to a picture, even if you didn't mean to save them.