Try to run a good malware scan with the free versions of MBAM and SAS to see
if there is a problem with something preventing SpySweeper from running.
Also a good anti-virus scan. If it all comes out good, try uninstalling the
program again and go back to a restore point where it was working, if
possible. You didn't state your OS.
Buffalo
PS: Have you tried Webroot's forum?

Ellwood P. Farquad wrote:
> Seems like I've had it forever, but lately is simply doesn't "run",
> just sits there "loading". Nothing is enabled, so all I see is the
> shell, and the program entries in Task Manager. 'Course when I try to
> end the process I get slapped down as not having privileges.
>
> Uninstalled it twice and re-installed to the Prog Files (x86),
> but still it just sits there "loading".
>
> Now I've uninstalled it again. Should I just bag it?
>
> P. S. As you'd expect you get NO help whatsoever from their
> support folks. Hey, they've got my purchase price money,
> why should they care?