You can read these articles:

http://www.ehow.com/how_8550801_can-firefoxexe-use-less-memory.html http://www.ehow.com/how_5187136_speed-firefox-use-less-memory.html http://www.ehow.com/how_8410197_make-use-less-memory-usage.html

Most of the time you just need to get more memory installed if you have other applications open along with multiple windows and tabs open in Firefox.

thanks.

I opened my extensions, and all are disabled, except ADBLOCK. I usually clean my history on weekly basis, sometimes even on daily basis.

When I use firefox, most of the time ther is no other application in use by me (I don't encounter all those back apps for the system). Most of the time, I have only 2 windows open , very rare there more.

The issue is that even at starting of firefox session I can see in task manager there is minimum 95 MB or charge, without any work done by me. I usually have charge about 370-390 MB of RAM, but when I open Firefox it gets me up to 500 or more.