CRM provides the standard way of uploading leads from excel sheet. Sometimes you may face the problem with the leads not getting uploaded properly.

Thinking from all the direction you may come to the conclusion that this is the issue with the CRM, but it is not. It is related with Security rights to Microsoft Excel Application in windows.

To resolve this, go to
Settings -> Control Panel -> Administrative Tool -> Component Service ->

Find the “Microsoft Excel Application” from the list of Component Services.

Right Click on that and go to the Properties.

Here select the Security Tabs.

Add internet user (IUSER) in list and give him the full access rights and the Problem is resolved.