Android Question Emulator set up first time

I am a novice. I have waited 90 minutes for the Virtual Device Manager to set up the Emulator for the first time and feel that this is far too long. I know the book says it can take a few minutes, but....
I have checked and double checked that all download, installation & input up to now is what is required and correct. I have a green tick in the box against the AVD entry so all should be well. Any suggestions as to where I am going wrong?
David.