Backing up c:\users directory with USMT

>I need to re-image my Vista Business laptop with the manufacturer provided
> "reload to factory" image from the system recovery partition. As this
> will
> completely reformat my hard drive I need to preserve the data in the
> c:\users\username directory or I will lose a lot of work.
>
> Can I use the User State Migration Tool (USMT) to save all this data
> before
> the re-image and the restore it afterward?
>
> Is there another tool to do this?
>
> Simply copying the c:\users directory doesn't seem to work because many of
> these files are "in use" and cannot be copied.