I cant delete a folder on my computer?

There's a folder thats driving me nuts, it appeared in my D: disk about half hour ago and I cant delete it despite my many efforts. I have changed the ownership of it to myself and given myself full control etc through properties despite me being administrator and the only user on the computer. I still cant delete it, Im not a huge braniac on the computer so if you guys could please answer the question really simply. I dont want to hide it, I just want it gone.