tazandq said

When I click on Firefox to open the browser window nearly 1/2 of the time it never opens. It shows that it is trying to open and then it does not. No matter how many times I click on it it will not open unless I reboot my computer.

I am experiencing the same issue running 35.0.1 on XP but it is more like 20% of the time. Task Manager shows firefox.exe using about 100,000K memory but the application is frozen and never show on screen. I end the firefox.exe process and start it again. Once in a while it takes more than one try.

Start Firefox in Safe Mode {web link} While you are in safe mode;

Type about:preferences#advanced<Enter> in the address bar.

Under Advanced, Select General. Look for and turn off Use Hardware Acceleration.

Poke around safe web sites. Are there any problems?

Check for crash reports;

In the address bar, type about:crashes<enter>. Note: If any reports do not have BP in front of the numbers, click it and select Submit.

Using your mouse, mark the most resent 7 - 10 crash reports, and copy them. Now go to the reply box below and paste them in.