DVD RW can't write DVD under Win7

My Toshiba Laptop has an Matshita DVD-RAM UJ890AS. I try to write a DVD disc, but it does nothing. In Win7 Explorer after selecting some files, the "write" button does nothing. I try to setup the Ashampoo Burning Studio, but it does not start - after the welcome screen happens nothing. I try to remove upper and lower filter - as microsoft says. In group policy the cd burner is enabled. ...