ArcGIS 10.1 Standard Hangs on Initializing Application

Hi,

I'd installed ArcGIS 10.1 Desktop on Windows 8 64 bit machine. When I try to open ArcMap it hangs at the stage of Initializing Application. The ArcCatelog is working fine.
I'd re-installed the application and installed the SP1 also. but problem is as it is.

Please help me.

regards

Indra Bisen