Quote from: forwardded on February 02, 2016, 07:49:11 PM

i sent half of a bitcoin to a wrong address

Woah, you should re-check the Bitcoin address before you hit the send button.

Quote from: stepwilli on February 02, 2016, 08:23:45 PM

My worst mistake with regards to bitcoins is that I used blockchain before and my wallet got hacked due to a virus. From then, I am only using offline wallets and on a pc which is not connected to the internet. I also advise others to not use online wallets.

You did not enable two-factor authentication on your Blockchain account? I'm still using Blockchain to store a few bits, never get hacked... yet.
Well, the core itself is the best alternatives.