Removing Codecs

Under Windows 95/98, codec entries are stored in SYSTEM.INI. All installed codecs appear in the codec dialog box in the order in which they are listed in SYSTEM.INI.

[drivers]
VIDC.MJPG=CAPCDC.drv        ;miroVIDEO DRX MJPEG codec

[drivers32]
VIDC.MP43=mpg4c32.dll       ;Microsoft MPEG-4 V3
VIDC.MJPX=pvmjpg20.dll      ;Pegasus PICVideo (secondary MJPEG codec)

Under Windows NT, 2000 or XP codec the entries are stored in the Registry, with VIDC.xxxx as the key and the driver name as the value. 

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Drivers32

Or

HKEY_CURRENT_USER\Software\Microsoft\Multimedia