We faced this problem while installing CRM outlook client in one of our laptops.
I followed the instructions mentioned below which i found while searching for the same.
On the client computer open the control panel.
Open the User Accounts icon.
Click the Advanced tab.
Click Manage Passwords.
Enter the server name of the CRM server
Enter the username as domain\username
Enter the password.
Click OK, then click Close and then click OK.
On the client open IE, click the Tools menu and then click Internet Options.
Click the Security tab.
Click the Local Intranet icon.
Click the Sites button.
Click the Advanced button.
Enter the website for access Microsoft CRM and then click the Add button.
Click OK 3 times.
Close any open IE sessions.
The problem got solved for us !