I had similar issues with W7. There is a dll file that got downloaded with a windows update that runs itself up until it shows errors and/or freezes the computer. I used Task Manager to watch the file go to a gig of RAM... Later versions of Firefox hog some memory anyway, and when this dll gets fired up, the two of them will use up a lot. Windows knows the update creates instability in some platforms. I had to uninstall two updates, one that nagged me about Windows 10 (GWX.Exe) and the other one that created this error.