I downloaded bittorrent then decided that I did'n want it, so uninstalled
it. The problem now is that everytime I switch on my computer I have
btdna.exe running in the background. How do I get rid of it please?
Install "ccleaner" from ccleaner.com,this is free, select "tools" and
then 'add remove programs" and remove it there. If it doesn't appear
there, then select "start up" in Ccleaner and remove it there.
CCleaner generally works where "uninstall doesn't do the job.
Then have a look in control panel/C drive/programs and delete the
folder that's left.