If you are trying to mine bitcoins: dude, what do you expect! A single block reward is 25 BTC, worth over € 2000. You think you will just somehow magically earn that kind of money by leaving your PC on for a few nights? Wake up

Forget about mining bitcoins, just
buy them. It's faster, easier, cheaper, and better for the environment

And preferably use a different exchange than MtGox (nothing particularly wrong with MtGox but others are cheaper, faster, and more diversity and competition is better for the Bitcoinomy).
Right
And a Bitcoin client will make no bitcoin, just keep them in safe