Like Kemical, I have no knowledge of PS's
One of my family mebers has a PS3. He is no PC expert but tells me this.
There is no way to read the data from a PS3 harddrive by using a PC. It is just a different file system. Windows PCs can't read the file system. Some linux gear can see the HDD, and he suggests you download a live Ubuntu ISO and make a cd . Run it and try and extract any info you can from the HD.
He also warns (not sure) that you should not, for the moment, connect the HDD back on to the PS3, as it will automatically be reformatted.