1. Reset your Internet Explorer web browser. This generally solves most plugin errors. To reset your web browser click the 'Tools' button and click 'Internet Options.'
2. Click the 'Advanced' tab and click 'Reset.' Select the 'Delete personal settings' check-box if you want to delete browsing history.

3. Click 'Reset' again in the 'Reset Internet Explorer Settings' box. Click 'Close' when the resetting process is complete. Close and relaunch your web browser. Move to the next step if you are still running into plug-in errors.
4. Enable the ActiveX and plug-in settings. To do so, click the 'Tools' button on your web browser and click 'Internet Options.'
5. Click the 'Security' tab and click 'Custom Level' to open the security settings window. Scroll down and select the 'Run ActiveX controls and plug-ins' radio button if it has not already been selected. Click 'OK' to save the changes and 'OK' again to close the Internet Options console. Restart your web browser.
6. Uninstall and reinstall the plug in if you are still running into errors. To do so, click the Windows 'Start' button and click the 'Control Panel.' Double-click 'Add or Remove Programs' to open the programs window if you are a Windows XP user. Click 'Program and Features' and click 'Uninstall a Program' to launch the programs window if you are a Windows Vista user.
7. Scroll through the programs window and click the plug-in (e.g. Adobe Flash player) running into errors. Click 'Remove/Uninstall' and uninstall it from your computer. Navigate back to the website you originally downloaded the plug-in from and download it again. Restart your web browser once the download is complete.