To start as the story went-

I was replying to a post on this forum and I had a power failure. Then after electricity was back (about 10minutes later), I started the PC again and then I could not connect to the internet, mIRC was also not WORKING. Some work caused me to hibernate it for a while.
 
Then after resuming the session, I still could not connect to the internet, so I called the ISP, after asking a few questions, he asked me to restore it to a previous time the latest was 30 November so I chose that,  and restored.

After restoring it, Internet Explorer and mIRC were working but FIREFOX was not, I tried, then I reinstalled Firefox, then when I tried to run it,  it said that it had unexpectedly quit, and asked whether I wanted to resume my older session or start a new session, I SELECTED start a new session, nothing happened.

I could see that the firefox.exe process was running (used Windows Task Manager), I ended the process.

Now when I start Firefox, the firefox.exe process is seen running in the Windows Task Manager but for less than one second and then it disappears.

Thanks. I assume this is Firefox 3, not FF2?

I also assume you've restarted the computer?

If so, TRY clearing Firefox's cache.

If that still doesn't work, create a new Firefox Profile and see if it works.
http://kb.mozillazine.org/Creating_a_new_Firefox_profile_on_WindowsHi Carbon,

How do I clear Firefox's cache?
After typing "firefox -P" nothing happens.Download and install CCleaner.
Have it clean your Firefox Cache.You may need FF clean install: http://kb.mozillazine.org/Uninstalling_FirefoxThanks BRONI, cleaning the install and reinstalling it made it fine.
Thanks Carbon for a nice utility.Heh, all right.

Good job Broni.I'm glad, it worked