Built in debugging in IE 8 and 9

F12 in IE 8 and 9

For Java script debugging and built in network monitor in IE9 press F12

Enable Script Debugging first.

Before debugging, open an IE browser and make sure in:

Tools->Internet Options->Advanced->Browsing

Disable script debugging (Internet Explorer) is unchecked

 

IE 8 JavaScript Debugger

https://msdn.microsoft.com/en-us/ie/dd699458

IE 8 JavaScript Profiler

https://msdn.microsoft.com/en-gb/ie/dd490714

IE 9 Developer Tools

https://msdn.microsoft.com/en-gb/ie/hh545573

Built in network monitor skip to 25 minutes

 

Best Regards

Dynamics CRM Team