Most modern websites (YouTube, Gmail, etc.) will not load correctly in IE8 because it lacks support for modern HTML5 and CSS3 standards.
While Microsoft no longer officially provides a "portable" package for IE8, the community has created standalone versions using virtualization technology (like ThinApp or Spoon). Step 1: Find a Reliable Source
Introduced the SmartScreen filter to protect against phishing and malware. How to Download and Use IE8 Portable for Windows 7
