Problems to get Uno connected to Win8.1 64bit...

Hello Forum,
I'm having problems to get my Uno connected to my Win 8.1 64bit system.
This problem occurred after a rebuild of my system to the latest 8.1/64. My previous installation was 8.1/32 worked fine.
I'm using Arduino 1.0.5-r2 - the latest released version with fixes for Win8.1.
Problem description:
When I connect my Uno to the USB I hear the windows sound for a new connected USB device but a few seconds later I heard the sound of disconnecting again.
Tried also the beta version (Arduino 1.5.6-r2 BETA ) but no difference. Tried several reboots but does not help.
My system simply does not want to see the board...

Please Help!

Problem fixed!
I found there was a problem in the sircuit on my breadboard.
After removing some wires I could connect the Uno without problems to my pc.
Thanks!