Can't backup my server

[PhansaP]

Dear All,

I use for plesk 9.2.1 windows version ,but I can't backup my plesk with schedule backup .
It's show message "Unable to find Backup dump object" in error log.

I see this "Cannot open backup through Parallels Plesk Panel: 'Unable to find Backup dump object' " ,but it's support for linux only not support for windows.

please Help.
Regard
Phansa P.