iMac and Photoshop problem

I needed a new hard drive and they've upgraded my OS to Yosemite.
It took several phone conversations with a Mac technician for us to find my iPhotos ... phew .. that was scary but my Photoshop CS 5 is not working and the Adobe site is rubbish.
Tried phoning them too but it's all automated and there's nothing to help me.
Have posted my problem on their site but no response. Have now written to Adobe in Ireland .... not holding my breath !

Meanwhile, I can open my existing PSDs and mess around with them to some extent, but I can't open JPGs in photoshop ... I get the message 'configuration error 15'

I'm not getting anywhere with this .. no response from Adobe.

There's another computer repair shop but I know nothing about the people. Spoke with them and they say they can sort it but how do I know if I can trust them with all my info on here ?

It seems odd that they can do it but the Apple shop who did the hard drive can not help.