Unconfirmed transaction since 2 days
Most likely the fee was very low and it is therefore not being selected by miners for a block. Bitcoin-Qt 0.8.6 is from Dec 2013 and you should consider upgrading to a newer version of the software. The recent versions have vastly improved fee estimation.

You should probably try to doublespend the transaction with a bigger fee. You can find more information and detailed instructions on Why is my transaction not getting confirmed and what can I do about it?.