I was trying to update Windows Defender in XP but the application declared that error code 0x80241001 prevented this. Afterwards my browser, Firefox, kept crashing. Alan Braddock
The error code indicates that an update was not installed successfully. The Microsoft Knowledge Base describes two ways to fix the problem (http://support.microsoft.com/kb/943144). If that doesn't stop Firefox crashing, try uninstalling Firefox 2 and then reinstalling either Firefox 2 or 3.