taking ages to delete user account on macbook pro?!

Hi,

I'm deleting an old user off my macbook pro and setting it up for another user, however it is taking AGES (25minutes so far....) to delete. The System Preferences won't let me quit as it says it's still working and under the account it does say "Deleting account" However I now cannot click or highlight this account.

I'm not convinced it's still working as it's taken so long. Is this a normal length of time to wait?

Thanks

Emily