I have figured out that Firefox is consuming a lot of processing power and at times it locks up and eventually manages to finish whatever it is doing and other times I can only just do a hard shut down to use the computer again. I have been using Avast Home anti virus and backing it with Malewarebytes and between these two softwares I have managed to keep this machine clean. CCleaner is used to manage keeping certain folders empty like the Temporary folders. This problem is not limited to any particular operation in Firefox (ie. watching streaming videos, typing, browsing the internet, pretty much anything FF does). I have managed to rule out the Add ons being the issue. I also looked for other programs that may affect this machine. the thing is I noticed this behavior on other machines too. Also when shut down there are times FF either out right refuses to shut down or it takes forever for it to shut down. Another issue is when shutting down firefox there are times it will remove itself from the desktop (imitating a shut down) but when I open the task manager it is still running and using a lot of processor. The computer has been swept thoroughly for any infectious software doing a boot scan with Avast and a deep scan using Malewarebytes in safe mode after updating its data base. I likewise have scanned it for any shadow software (spyware, peepware, "hidden" programs) and so far I have found nothing. All drives of this machine have been scanned. The computer is a Gateway Shuttle, Intel Celeron 2.66 GHz,512 MB of RAM dual 80 GB HDDs. These performance issues are not present in Internet Explorer (Boo hiss). Likewise the issues described here were not present in the previous version of FF I had installed on this computer. They did manifest shortly after installing the latest version of Firefox.