Thank you for your reply. I waited ages and ages for the activation email for registration but never received it, so I have registered with another username, but I am the above poster, Emily.
I didn't actually overwrite the original variable, I always make sure I keep all raw data. In the end I windsorised more of the extreme values, as I had been very conservative to begin with, and this seemed to solve the skewness to some degree.
Many thanks for your help though. I actually have another question now which I have just posted!