Is My SoundCard Crashing My PC ?

Sorry, with Cubase 7 I can’t agree with that as you’d really have to know your system, components and software. Cubase 5+ is a possibility, even C6 at a very knowledgeable push. In any event Cubase is a huge, very complicated and convoluted piece of work. I have seen so many here having continual problems with underpowered rigs. More than a few insist it’s Cubase and that they really know their stuff but they continue to have issue after issue.

If you only have moderate studio ambitions, band recordings, composing and the like and you can’t afford the system to go with the software; well if that was me I’d get the lesser powerful software in the first place. Sequel even. Reaper’s fine. Cubase does so much in the background it’s impossible to tell why any particular part of an underpowered system would fall down or why.
Saying that I really think that Steinberg should put a much higher minimum spec on the boxes for Cubase and push their lower down software for (non-orchestral) composers and they’d have a lot more happy customers with understressed and more modest systems. My opinion is that it’s at least as powerful, if not more, than Nuendo which many here with long term problems wouldn’t dream of investing in.
You build a good house from the ground up and not buy a gilded roof first and struggle keeping it off the ground.
The carpet goes down first, not the furniture.