User Profile Synchonization Service Stuck on Starting

Starting User Profile Synchonization Service in SharePoint is always a big pain. Most of the time it stuck on Starting mode and you dont have controll to stop this.

You can stop the User profile Synchronization Service.
http://donalconlon.wordpress.com/2010/08/27/deleting-the-search-service-application/

There are many reasons for this.

1. The account which you are using to run the service might not have "Replicate Directory Changes" permission in your AD.

Solution:
http://www.codeproject.com/Articles/358855/user-profile-synchronization-service-not-starting

2. This account which you are using to run the service  might not have explicit access to the folder C:\Program Files\Microsoft Office Servers\14.0.

The reason we need to give explicit access to the folder is User Profile Synchronization service access AD through ForeFront Identity Manager Synchronization Service.

Thus in order to start User Profile Synchronization Service, Microsoft Forefront Identity Manager Synchronization Service have full access and this Forefront Synchronization service sits at C:\Program Files\Microsoft Office Servers\14.0.\Synchronization Service\UIShell called as miisclient (Microsoft ForeFront Identity Manager).

Solution: Give access
http://melick-rajee.blogspot.com.au/2011/07/user-profile-synchronization-service.html

3.The password for the account which you are using to run the service is not correct.

Solution: Enter proper password or if the password is expired reset the password in AD and then  following the below link
http://info.izzy.org/Blog/archive/2010/08/04/how-to-fix-an-out-of-sync-password-issue-in-sharepoint-2010.aspx
http://blogs.technet.com/b/seanearp/archive/2011/01/25/updating-passwords-on-sharepoint-2010.aspx

Hope this help.
Cheers
Isha