1. Try reinstalling into your browser:

• Internet Explorer:
  • In IE, download this link (IE6+) - https://lastpass.com/download/cdn/lastpass_x64.exe
  • Follow the instructions to install.
• Chrome:
  • Ensure that you are running the stable release version (Chrome 18+)
  • In Chrome, download this file - https://lastpass.com/download/cdn/lpchrome_win.crx
  • If it does not automatically install, manually install by dragging and dropping the .crx file into your Chrome's Extensions page (chrome://extensions/)
• Firefox :
  • Ensure that you are running the current release version (Firefox 2.0+)
  • In Firefox, download this file - https://lastpass.com/download/cdn/lp_win.xpi
  • The .xpi file will prompt to install and then automatically install.
  • Restart the browser after installing
• Opera :
  • Ensure that you are running Opera 11+
  • In Opera, go to the Add-ons page - https://lastpass.com/lpopera.php
  • Click on +Add to Opera, and confirm to install
• Safari  (Windows):
  • Ensure that you are running Safari 5+
  • In Safari, download this file - https://lastpass.com/download/cdn/lastpass.safariextz
  • Click open, then click install
• Safari (Mac):
  • Ensure that you are running Safari 5+
  • In Safari, download this file - https://lastpass.com/lastpass.safariextz
  • If it does not auto-prompt for install, go to your downloads and double-click the lastpass.safariextz file to manually run the install.
• Maxthon :
  • Ensure that you are running Mathxon 4.0.3.3000+
  • In Mathon, go to the Extension Center - https://lastpass.com/lpmaxthon.php
  • Click on Install > Install

2. If you still do not see LastPass in your browser, please go into your browser's list of Extensions and ensure that    LastPass is listed there AND enabled.

3. Try right-clicking over the browser toolbar area to see if LastPass is present and checked.

4. If a reinstall is not working, please temporarily disable any other addons/extensions or themes and try again.

5. Some antivirus and other security suites are particularly aggressive and may be blocking installation - make sure that LastPass has been marked as a trusted source before installing. 

6. If the toolbar disappears intermittently, please check that a PC tune-up program like System Mechanic or CC Cleaner is not wiping away the files.  If you have System Mechanic, follow these directions to make an exception for LastPass.