# Upper & Lower Filters



## josh126 (May 3, 2009)

I recently had to repair a Toshiba Satelite Laptop which had a CD/DVD Drive that wasn't being detected by the OS (VISTA).

I did checked the device manager and found an error on the DVD drive driver, Error 19

I did a bit of research and found a common solution was to refresh the Upper and Lower filters within the registry. After completing this the DVD drive worked fine.

I am just here to see if anyone can give me an explanation on what these "Filters" are.

Thanks


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## Elvandil (Aug 1, 2003)

Filters are add-on drivers that ride on the coattails of the main drivers. Often filter drivers are installed by other programs that need access to the drive and the filters remain after the programs have been removed, preventing the drivers from loading properly.


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## josh126 (May 3, 2009)

Awesome, thanks for the help.


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## Elvandil (Aug 1, 2003)

No problem. I used to think that it was always Roxio that left those remnants behind, but some people swear they never had Roxio, so I don't know now. I suppose with all the multimedia programs with built-in burners, it could be more than one application that does it. Or Gremlins.


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