Thanks for the help, managed to clean the system 
Did what you said in Hijack This!, which got rid of the drwtsn thing, then ran malwarebytes, spybot: S&D and CCleaner. I'll run Combofix and Cleanup! next time I'm round, but the system is now working perfectly and much faster.
Curiously I was unable to install Ubuntu, it wouldn't let me do anything with the partitioner.
Did what you said in Hijack This!, which got rid of the drwtsn thing, then ran malwarebytes, spybot: S&D and CCleaner. I'll run Combofix and Cleanup! next time I'm round, but the system is now working perfectly and much faster.Curiously I was unable to install Ubuntu, it wouldn't let me do anything with the partitioner.
