After runing CCleaner the first time my laptop (Acer Travelmate C110) really worked as new again, but I don't know what did I erase and my modem doesn't work anymore, if I try to begin a dial-up connection an error message appears telling me that the modem is busy in another application (and is not). The LAN and wireless connections work well. I don't remember if I kept the log of the first cleaning.