The only solution I know of is to use Cleaner 5 (PC version
only).
For Cleaner 5 to accept the WMV-file you have to rename the
extension of your source file from WMV to ASF.
I have to say that Cleaner 5 has given me lots of trouble,
it crashes a lot! Often it crashes when in the advanced
settings dialogue, but I've found that if you save your
setting after every parameter change you are more likely to
finish without it crashing on you...