Method One
1. Click on the 'Start' menu, and click on 'Control Panel.'
2. Click on 'Uninstall a Program' under 'Programs.'

3. Click on 'Turn Windows features on or off' in the left pane. A new window will open.
4. Uncheck the box next to 'Internet Explorer 8' (or whatever version of Internet Explorer you have) and click 'OK.'
5. Go to the link in Resources and download the current version of Internet Explorer. This should fix the Mshtml.dll file. If it does not, continue to the next method.
Method Two
6. Click on the 'Start' menu, and click on 'Run.'
7. Type 'cmd' (without the quotation marks) into the open box and click 'OK.' The Command Prompt window will open.
8. Type 'regsvr32 Mshtml.dll' (without the quotation marks) into the Command Prompt window and press 'Enter.' This will re-register the Mshtml.dll file.
9. Restart your computer.