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
Helpful replies
You can install that update and use Firefox if you Disable Hardware Acceleration in Firefox Turning off hardware acceleration
Go to answer 6Additional System Details
Installed Plug-ins
- 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
- SiteAdvisor
- Adobe PDF Plug-In For Firefox and Netscape 10.1.4
- 5.1.10411.0
- The plug-in allows you to open and edit files using Microsoft Office applications
- Office Authorization plug-in for NPAPI browsers
Application
- User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:19.0) Gecko/20100101 Firefox/19.0
More Information
Helpful Reply
You can install that update and use Firefox if you Disable Hardware Acceleration in Firefox Turning off hardware acceleration