That crash report points to a file, NOWImaging_Moz.dll, as the likely cause of the crashing. This file is not a part of Firefox, but a Google search indicates it is part of an extension, probably SlipStream SP Image Decoders. Check your list of extensions, if you have that one try disabling it to see if that stops the crashing. To disable an extension do this: # Click the Tools menu and then select Add-ons . The Add-ons window appears. # In the Add-ons window, click the Extensions panel. The list of installed extensions appears. # Click the name of an extension the list to select it. # Click Disable to disable the selected extension. # Click Restart Firefox .