No need to access the folder: a single click on the Continue button brings up file permissions.

When an operation on a file is pending, simply click the Allow button to permit it to proceed.

When erasing files, Vista shows detailed information.

As you look at the giant file icon, it isn't exactly clear whether the file is actually being erased, or is just being moved into the recycle bin.

The file is in use, but Windows won't say which program is using it.