FYI: Microsoft update for Windows 7 KB2670838 (date 2/28/2013) kills Firefox
Spent the entire morning troubleshooting this.
KB2670838 prevents FF from starting except in safe mode.
I downgraded from 19.0 to 18.0, same problem.
Went thru my entire system, reinstalled FF, nothing. The only difference in my system this AM was the MS update above. I removed it, rebooted and FF worked fine.
Modified by izaakb
Additional System Details
- Shockwave Flash 11.6 r602
- Adobe PDF Plug-In For Firefox and Netscape 10.1.6
- Next Generation Java Plug-in 10.9.2 for Mozilla browsers
- NPRuntime Script Plug-in Library for Java(TM) Deploy
- Adobe PDF Plug-In For Firefox and Netscape 10.1.4
- The plug-in allows you to open and edit files using Microsoft Office applications
- Office Authorization plug-in for NPAPI browsers
- User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:19.0) Gecko/20100101 Firefox/19.0
You can install that update and use Firefox if you Disable Hardware Acceleration in Firefox Turning off hardware acceleration