N360 won't Install on Windows 8.1

I've been using 360 for a while, current licence expired & I purchased a new multi-device licence.

I've installed it after a fashion on 2 devices, however my older PC won't fully install the product.

I've ran the removal & power eraser tools a number of times.

Each time the install from the Norton site, get as far as Installation complete restart required and it won't then fire back up - only option is to restore machine. Or it tries to install and I get a blue screen / page fault error and the machine crashes and then again only option is the restore option. I've tried the safe boot, but that didn't work?

Any ideas?

Regards

Ian