I was an early user of Firefox and continue to support the Open Source browser. Last year my computer (Dell Latitude E6500 running Windows XP) began to have problems keeping up with Firefox. I recognize that I have a lot of very useful Extensions and a good number of Add-ons and a few plugins. However, seeing my CPU hit 100% on a regular basis became unacceptable. Firefox will have 50% or 60% of the total CPU and the laptop becomes unusable as it grinds to a halt. Power Off.
What’s the Cause
I have no idea yet. My guess is that it may be something to do with Video, Anti-Virus or something installed on Firefox.
If I run TweetDeck (an Adobe Air application) along with Firefox 3.6 and then run Safari 5.0.3 and play something on Hulu (not full screen), eventually the CPU will hit 100%. The interesting part is that even after Closing all three of these applications the CPU remains at 100%. That is frustrating.
I Tried Chrome.
It was surprising to see how many plugins are available for Chrome. After installing a bunch I made Chrome the default browser. But over time I didn’t like the way RoboForm is implemented and a few other Extensions that I missed made my daily browsing more difficult than it needed to be, so I reverted to Firefox.
Uninstalling AVG provided some relief. I am still testing, but removing AVG seems to have eliminated the problem of the CPU staying at 100% even after closing the applications. Now, after closing the apps the CPU returns to a restful state.
Installed Firefox Extensions and Plugins
Do you know which Firefox Extensions might cause heavy CPU usage? Below is a list of everything installed on Firefox.
My Config- default
Generated: Sat Jan 08 2011 09:14:23 GMT-0500 (Eastern Standard Time)
User Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:18.104.22.168) Gecko/20101203 Firefox/3.6.13 ( .NET CLR 3.5.30729)
Build ID: 20101203075014
Enabled Extensions: 
- AI Roboform Toolbar for Firefox 6.10.1 – Allows the use of Roboform in Firefox.
- ColorfulTabs 4.6.5 – Colorful Tabs colors every tab in a different color and makes them easy to distinguish while beautifying the overall appeal of the interface.
- ColorZilla 2.2.2 – Advanced Eyedropper, ColorPicker, Page Zoomer and other colorful goodies
- Domain Details 2.6.8 – Displays Server Type, Headers, IP Address, Location Flag, and links to Whois Reports
- FEBE 22.214.171.124 – Backup your Firefox data
- Firebug 1.6.1 – Web Development Evolved.
- FireFTP 1.0.10 – FTP Client for Mozilla Firefox.
- Fission 1.0.9 – Progress bar in the address bar (Safari style).
- Greasemonkey 0.8.20100408.6 – A User Script Manager for Firefox
- Html Validator 0.8.6.1 – Adds HTML validation to the View Page Source of the browser. The validation is done by Tidy from W3c.
- Java Console 6.0.22
- Java Console 6.0.23
- Java Quick Starter 1.0
- Link Diagnosis 1.2.2 – Examine link competition
- LinkChecker 0.6.6 – Check the validity of links on any webpage.
- LinkDiagnosis 2.2 2.2.41 – Examine link competition using the new and improved Link Diagnosis Tool
- Live HTTP headers 0.16 – View HTTP headers of a page and while browsing.
- MeasureIt 0.4.6 – Draw out a ruler to get the pixel width and height of any elements on a webpage.
- Microsoft .NET Framework Assistant 1.2.1 – Adds ClickOnce support and the ability to report installed .NET Framework versions to the web server.
- Move Media Player 7 – Media Player
- Mozbar 0.51 – A toolbar for the users of SEOmoz.org, Inc.
- MR Tech Toolkit 6.0.4 – MR Tech Toolkit power tools for all users. (en-US)
- NewsFox 1.0.5 – RSS/Atom News Reader.
- PDF Download 126.96.36.199 – Allows you to choose what to do with a PDF file: download it, view it with an external viewer or view it as HTML.
- RankChecker 1.7.9 – Track where your site ranks in Google, Yahoo, and Microsoft Live Search using the free Firefox rank checker.
- Screengrab 0.96.3 – Saves a web-page as an image.
- SearchStatus 1.33 – Display the Google, Alexa, Compete and Linkscape ranking with search-related tools.
- SEO Blogger 1.0.4 – Wordtracker’s SEO Blogger extension
- SEO Doctor 1.4 – Calculate link statistics of the current website
- SEO For Firefox 3.4.2 – SEO information inline with Google and Yahoo! search results
- SEO Link Analysis 1.0.7 – Adds display of PageRank, linktext and nofollow links to external links in Google Webmaster Tools and Yahoo! Site Explorer
- Seo Toolbar 1.1.3 – The SEO Toolbar allows you to look at on page and off page competitive research details from the convenience of your Firefox browser as you browse the web. It also allows you to find keywords by putting many keyword tools at your fingertips. Have SEO questions? Ask them in the SEO Book Community Forums!
- SEOpen 1.1 – Provides some basic tools to help with search engine optimization.
- Session Manager 0.6.9.3 – Saves and restores the state of all windows.
- StumbleUpon 3.76 – StumbleUpon Toolbar
- Tab Mix Plus 0.3.8.4 – Tab browsing with an added boost.
- Total Validator 6.9.1 – Validates web pages in numerous ways
- Update Notifier 0.1.5.5 – Notifies you when updates are available for your extensions and themes.
- Web Developer 1.1.9 – Adds a menu and a toolbar with various web developer tools.
- Website Health Check Tool 1.1.3 – The Website Health Check tool aims to provide a simple and intuitive interface to seeing if your site has any major SEO issues.
- YSlow 2.1.0 – Make your pages faster with Yahoo!’s page performance tool
Disabled Extensions: 
- After the Deadline 1.50 – After the Deadline checks spelling, grammar, and style in your web forms.
- BlekkoToolbar 1.0.2 – Blekko’s Search Toolbar
- Ghostery 2.4.2 – Ghostery identifies and allows you to block the 3rd parties (web bugs) that are hidden on the current page you’re visiting. Web bugs include ad networks, behavioral data collectors and web analytics providers.
- HP Smart Web Printing 4.60 – Print what you want, how you want.
- SeoQuake 2.6.8 – Quick view of site parameters in the search engine results pages.
- SeoQuake Plugin – Ask.com 1.0.6 – SeoQuake Plugin – Ask.com
- Speed Dial 0.9.5.8 – Direct access to your most visited websites
Total Extensions: 48
Installed Themes: 
Installed Plugins: (28)
- 2007 Microsoft Office system: NPOFF12.DLL- Office Plugin for Netscape Navigator
- Adobe Acrobat: nppdf32.dll- Adobe PDF Plug-In For Firefox and Netscape “9.4.1″
- downloadUpdater: npdnu.dll- npdnu
- downloadUpdater2: npdnupdater2.dll- npdnupdater2
- Google Talk Plugin: npgoogletalk.dll- Version 188.8.131.52
- Google Talk Plugin Video Accelerator: npgtpo3dautoplugin.dll- Google Talk Plugin Video Accelerator version:0.1.43.4
- Google Update: npGoogleOneClick8.dll- Google Update
- iTunes Application Detector: npitunes.dll- iTunes Detector Plug-in
- Java Deployment Toolkit 184.108.40.206: npdeployJava1.dll- NPRuntime Script Plug-in Library for Java(TM) Deploy
- Java(TM) Platform SE 6 U23: npjp2.dll- Next Generation Java Plug-in 1.6.0_23 for Mozilla browsers
- Microsoft® DRM: npdrmv2.dll- DRM Netscape Network Object
- Microsoft® DRM: npwmsdrm.dll- DRM Store Netscape Plugin
- Move Streaming Media Player: npqmp071500000347.dll- npmnqmp 989898989877
- Mozilla Default Plug-in: npnul32.dll- Default Plug-in
- QuickTime Plug-in 7.6.9: npqtplugin.dll- The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
- QuickTime Plug-in 7.6.9: npqtplugin2.dll- The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
- QuickTime Plug-in 7.6.9: npqtplugin3.dll- The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
- QuickTime Plug-in 7.6.9: npqtplugin4.dll- The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
- QuickTime Plug-in 7.6.9: npqtplugin5.dll- The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
- QuickTime Plug-in 7.6.9: npqtplugin6.dll- The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
- QuickTime Plug-in 7.6.9: npqtplugin7.dll- The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
- RockMelt Update: npRockMeltOneClick8.dll- RockMelt Update
- Shockwave Flash: NPSWF32.dll- Shockwave Flash 10.1 r102
- Silverlight Plug-In: npctrl.dll- 4.0.51204.0
- Turner Media Plugin 220.127.116.11: NPTURNMED.dll- NPTURNMED
- Unity Player: npUnity3D32.dll- Unity Player 2.6.1f3
- Windows Media Player Plug-in Dynamic Link Library: npdsplay.dll- Npdsplay dll
- Windows Presentation Foundation: NPWPF.dll- Windows Presentation Foundation (WPF) plug-in for Mozilla browsers
I welcome all suggestions leading to a resolution of this issue. Well, except the constant refrain from my friends to buy a Mac, unless of course you want to Chip-In. This is for you Phil and Chris and many others!!!
But, I digress. I really want to get Firefox running in a stable manner again. I think that removing AVG was a help, but it is not the solution. I will add notes here as various solutions are tested and proven effective or not.
All suggestions are welcome int the comment area below.
UPDATE: In a new post I describe how I have created a new installation of Firefox using PortableApps.
UPDATE 2: The version of RoboForm was giving errors. I upgraded RoboForm and I am no logger getting a script error. Removing Tab Mix Plus may also have beneficial. I also switched from AVG to Avira anti-virus program. I have TweetDeck, PortableApps Firefox and Hulu playing on Safari and things are running well so far.