Browser seems to hang !!!!

I use Firefox 4 and recently, whenever I browse the page seems to hang frequently !!! can anyone tell me what to do ??

I use Firefox 4 and recently, whenever I browse the page seems to hang frequently !!! can anyone tell me what to do ??
I will give you possible solutions for your problem:
1. Please update your Antivirus and have a full system scan ( You must have a Good and trusted Antivirus I recommend using Kaspersky and Norton)
2. Have a registry cleaner and fixer ( I will give you a link on the program that I am using http://www.piriform.com/ccleaner/download) Please download and install the program and Run it. Click on the registry and scan for issues and it will fix it.
3. If still the error occurs try upgrading your RAM or have a flash drive that is 4Gb or 8Gb and use it on ReadyBoost (for windows 7)
4. The page you are loading is heavy while you are running programs that require big RAM usage
You are using a very old version of Mozilla Firefox and I think one of the reasons why this happens is because of the updates being installed on your computer via Windows Automatic Update. You can reinstall Mozilla Firefox and see if this can fix the problem. Click Start, Control Panel, and then Add or Remove Programs.
Find and select Mozilla Firefox then click Remove or Uninstall. Open Windows Explorer then go to “C:Program Files”. Check if Firefox’s folder was removed when you uninstall it. If not, delete the folder manually. Run its installer again and see if it still freezes. If the problem continues, you can try on upgrading it since you are also using a very old version.
Visit Mozilla Firefox Free Download to download Mozilla 25 the latest version. Here are some of the modifications done in this version:
Visit Security Advisories for Firefox to see the latest security fixes on Mozilla Firefox.