My friend is facing this issue for last few days. He is not much technocrat so I am posting on behalf of him.
Whenever he starts laptop and after then starts Firefox (regularly updated to latest version), it hangs for 8-10 minutes and cooling fan noise increases noticeably. Also processor usage shows 80-90% during when it hangs. This happens for the first time only when he launches firefox after that he does not face any issue even after hours of browsing.
OS : Windows 7, 64 bits
Ram: 4 GB
Processor : Intel Core i3, 2.26 GHz
He has habit of closing firefox when multiple tabs are open and saves them before closing firefox.
Temporary files deletion using CCLeaner, Virus scan is already done.
Windows 7 is genuine and regularly updated.
Problem occurs even he starts firefox after 10 mins he starts Windows. Same problem he had with IE.
Is it because of some add on compatibility issue? Or bug in Firefox? Or too many startup processes? Any help will be appreciated.