It was an old 2D platform game with some small furry-like creature. You were on a quest to find the missing members of your family. You moved from scene to scene (rather than the screen following your movement) much like the old game Creatures. When you found a family member, they would reappear on a photo of your family home and they were all the same species but with distinct character designs (such as a grandpa).

I played this game once on my dad's place when I was young as part of the many games he had pirated for the PC (such as a PC version of Sonic 3 & Knuckles). So I have no idea where the game originated from. I'd very much appreciate being able to find this title again.

As far as I know there hasn't been a release of Sonic for the PC so that would've been ROMs and when you have to take those into consideration as well.. that's a lot of games.
The first things that came to mind for me were Legacy of the Wizard and Fury of the Furries.
Neither of those match exactly what you described, but they came to mind.

I definitely had a non ROM version of Sonic (this one I think: http://www.amazon.co.uk/Sonic-and-Knuckles-PC-CD/dp/B0006M5YPI) on the PC years ago, so that's not beyond the realms of possibility.

But as the OP mentioned pirating it's entirely possible that it's a ROM he's talking about, and I have no clue what it is.. Sorry.

I meant back in those days, I thought the first release on PC was back in 200X in a collection.
Apparently there was an earlier release as well, that's quite interesting.
Still a lot later than I had in mind when the OP said 'old', but I often forget I'm probably a bit older than a large portion of the current forumgoers :P

Not sure but it could be Cosmo's Cosmic Adventure: Forbidden Planet.

I have no idea when I had it... At least twelve to fifteen years ago? Whether that's old or not depends on your point of view I suppose ;)

Yeah, first thought I had was also Fury of the Furries but I couldn't remember the title.

It's unfortunately none of those titles you listed. Although the details are hard to remember, it had the graphics of a PC game (on level with Creatures or better). But the key to finding the game is the objective: If it's not about finding family members and making them reappear on a photo, it's not the game.

I appreciate your efforts though. I didn't expect this many responses so fast. :-)

Edit: The sonic game I mentioned wasn't an emulator (as in you didn't run the program and then mount a rom), but an individual program with Sonic 3 & Knuckles where you also could start the Blue Spheres side game from the file menu. He got these CDs loaded with pirated games like that and the game I mentioned was on one of them.

I remember that PC version as well. The funny thing is that Sega always had a PC division, but i guess they never really advertised it that much. Even stuff like Virtua Fighter, Virtual Cop and Panzer Dragoon were ported to the PC (not Panzer Dragoon Saga, though).