Do you have Norton installed on your computer ? If so you must disable the Norton Protected Recycle Bin" feature before you can empty the recycle bin.
If you don't have it, boot to DOS mode and type:
Thi deletes the entire directory and answer 'yes' to the subsequent prompt. It will be recreated on the next boot. Windows recycle bin will not be in a working state when you get back into windows. You'll need to then throw away a copy of file into it and then 'empty' the bin using the right click context menu choice. At this time you will be asked if you really want to delete x+1 files? x being the number of the files that were in the bin before you deleted it. Click yes and THEN you have a working, usable bin again.
Hope this helps.