make sure the server is fully patched with all windows updates, missing updates can cause problems with IE 11 or 10 and logging in.
check the windows application log to get more detail about the error if you post the error details then maybe we could help but without it not so much
Also I would double check the file system permissions sometimes funky permissions occur because the file system objects are owned by a user sid that doesn't exist on the new machine. The /Data and /App_Data folders and all their child objects must be under full read/write control of the user that is the identity on the app pool.
A variety of errors can happen if file system permissions are messed up.
See also Moving an Installation of mojoPortal and Basic Troubleshooting