How to access the photos in my old iPhone backup (on a PC)?

Wife and I upgraded our iPhone 3GS to the 4S. I use a Mac… She uses a Win7 laptop. Before going to the store, I backed up her iPhone to her computer. I don't know Win7 very well… So I need your help! We no longer have her old 3GS but she wants her old iPhone photos. How do I get them out of the backup? Nobody seems to have the answer no matter how much I Google and dig in the catacombs of windows directories. Gah! Why can't the whole world be perfect like a Mac? SMH

Get iCloud

IPhone backup extractor for windows