Dynamics CRM 4.0 is not compatible with IE10 and Higher. Likewise, our c360 Add-on Solutions for Dynamics CRM 4.0 are not compatible for the same reasons.
Microsoft’s compatibility chart for Dynamics CRM 4.0 can be referenced at: http://support.microsoft.com/kb/2669061
In addition, Microsoft's mainstream support for CRM 4.0 ended on 9-Apr-2013.
We do not anticipate Microsoft providing updates to CRM 4.0 to enable higher versions of IE in MS CRM 4.0.
Customers using CRM 4.0 that attempt to use IE10 or higher will likely experience issues. Reported issues include data not rendering correctly or java script errors displayed.