Thanks for the reply.
Using processing power to secure transactions make sense, but I still don't see why all the biggest datacenters should get the big part of the money.

I was not talking about resuming a mining operation, just how to keep my account and wallet when re-installing or switching computers.
I also won't try GUIMiner again unless I get an answer on that crash. Seems like there's a lot of other applications available, which one should be best for an high-end Intel+Nvidia combo on Windows7 x64?