Thanks a lot kovidgoyal!!!
I donwloaded the eBook Library
form Sony . With that update, I could reinstall and also made an installarion of the Sony USB Driver.
But The PRS was not recognized. I found that when I made the Uninstall of Libprs, somehow, the LibPRSDrivers were not unistalled. I donīt know why, but All I did was to uninstall the drivers manually and everything works PERFECT!.
Thanks for your help!