Hello, Im new here and trying to research some data on Internet History. When I open the file using notepad it says Client URLcache MMF ver 5.2. How do I open this file and view history logs and temp Int files?

See if this helps

INDEX.DAT tool helps admins see what users browsed in IE
INDEX.DAT tool helps admins see what users browsed in IE

Index.dat is binary format file, meaning you need a hex editor to fully view the contents as text editors such as Notepad may not show all the characters present in the file. The format specification of this file may be published somewhere in Microsoft's Technet or support knowledgebase documentation, and possibly elsewhere by Googling if you care to search for it. Otherwise you will have to figure out the format by yourself by browsing and noting how the file changes.

Once the file specification is determined, you would then need to write a file parser application to read the file and present its contents in a readable manner. I suspect someone somewhere has already done this, so Google "index.dat file viewer" or similar and see what you come up with.