ur824 malfunction

hi everyone ,

I’m no computer specialist, and English is not my mother tongue, I hope I’ll be clear anyway .

I just installed an UR824 on my brand new Pc ( i7 3.6ghz , 16 Go RAM , ssd disk , win 8.1 64 bits ).

… I can’t even read a mp3 without a slow down !!!

precisions , I had the hotline tech of my pc who guided me step by step for fixing it, we made tests , disabled the Realtek device in the BIOS and so on , there’s nothing to do about it .
(all cables are new , plugged correctly , the install was correct too ,I followed the manual and the UR824 appears in the configuration panel properly, the problem is there since I installed the genuine CD drivers , I then updated the drivers but still doesn’t work ).

the tech has never seen such a problem ( and neither I , I had several DAWS through the years .

any suggestions ?