That's part of your problem here. The 4530s only support max of 8G Ram. I'm assuming your using 8G+4G module to get that 12G. This will cause your CPU to work harder which result in overheating and/or freezing.
Even if it support more than 8G you should only use the same module speed and brand if possible. 8G+8G or 4G+4G etc...
Remove one of your memory module and use the module that came with you HP before you try anything else.