Which model Sony camera?
Camera Raw 8.8 did not add support for any new Sony cameras
Adobe Camera Raw comes in 3 flavours:
- Photoshop (full version) plugin
- Photoshop Elements plugin
- Lightroom update (Lightroom uses its own Raw engine)
You've downloaded 1) which will not help you with 2) or 3) both of which we are awaiting separate updates for.
In your position, use the free Adobe DNG converter, convert your .ARW files to DNG format then edit the DNGs in Elements 12.1 and Lightroom 4.4.
Thanks, why didn't ACR 8.8 update in PSE?
a) you have Elements 12 which is only compatible with ACR up to version 8.5. ACR 8.8 for Elements (when it is released) will not run on Elements 12
b) ACR 8.8 for Elements 13 has not yet been released. Only ACR 8.8 for Photoshop CS6/CC/CC 2014 - which is what you have downloaded but cannot use.
If you stay with Elements 12, you'll have to continue using the free DNG converter 8.8.
However, if you want to use ACR8.8 for Elements, you'll have to pay to upgrade to Elements 13.