Javascript:void is a web browser error that usually appears when the browser is running into problems loading the JavaScripts on websites you are visiting. Consider the following possible causes and solutions.

Pop-up Blockers

Sometimes these conflict with how your web browser interacts with the website you are visiting, resulting in Javascript:void errors. Try shutting down your pop-up blocker to see if this is the case. If it is, try using a different popup blocker.

Web Proxies

Although it's nice to surf anonymously, proxy services sometimes disable scripts by default. Many proxys have a "remove scripts" option enabled by default. You can try disabling that feature, or try using another proxy.

Web Browser

If you haven't updated your web browser in a while, you might be running into problems. If you suspect it may be a problem with your web browser in general, first try getting the latest version. The same goes with Java - update your computer to the most recent version. If you're still experiencing these errors after updating, then your preferences might be set incorrectly. Go into your browser options and disable anything that could be disabling the webpage scripts. And don't forget to check if Javascript is turned on - if it isn't then you've found your problem. Lastly, if all else fails, most browser have an option will allow you skips JavaScript error messages.

Bad Scripts

Sometimes there's nothing wrong on your end, but instead the website you're visiting has incorrect code. In this case, email the web administrator about the problem and hopefully they'll fix it.

For those not technically inclined, or for those who want to improve their computer performance overall, it is suggested that you download PC Health Advisor. It will scan your computer for any issues it has and fix the problems it has detected.