Photoshop :: Very Slow Lightroom 4.4 To CS6 In Windows 8?

I have a problem with my Windows 8 computer. notice that on this computer I did not change any of the default settings in the operating system, it is a clean install of Windows 8. I have also installed the latest version of Photoshop and Lightroom directly from my Adobe Application Manager software (I am a Creative Cloud member).
 
What happens is that I have to wait 30-50 seconds after I give, in Lightroom, the command "Modify in -> Photoshop CS6" (I have the software in Italian and I hope that this translation is correct. Here is the command that I am using:
 
The very strange thing that happens is that Photoshop opens fast (5 seconds, I have an SSD) and Lightroom is very fast too. Here is the strange thing. Photoshop opens after I launch the command.
 
Then nothing seems to happen for 30-50 seconds (sometimes also more time). After this “long” period of time this error appears in Lightroom:
 
It says: "you can't modify this file because Photoshop CS6 can't be started". However, this is not true! Photoshop is running correctly, and it was running! This happens if Photoshop was started from Lightroom and if Photoshop was running before Lightroom command "Modify in -> Photoshop CS".
 
Another strange thing is that, after I press "OK" to this error message, the file immediately opens in Photoshop!
 
notice that this behavior happens also with a series of file. If, for example, I export 10 files from Lighroom, then, after about one minute, I get 10 error messages in Lightroom, and, when I press OK, the files will open in Photoshop (for each "OK" that I press a file opens, so I have to press 10 times OK to open my 10 files!).