My computer restarted many times each day and drove me nuts. After three weeks I renamed the driver(?) FDCDNT.SYS, and the problems disappeared. The register is still trying to activate it, but can of course not find it. Location: c:\windows\system32\FDCDNT.sys I have been Googling, and Googling but havent found the answer. Found the name of the company that produces it, but couldnt find the company on the Internet. The process Filter Device belongs to the software Filter Device for WinNT/2k/XP by Silence of Troubles United Company Ltd. I checked the MD5 checksum. Does anybody know what program installed FDCDNT.SYS, and its purpose? I am grateful for any advice, and apologize if this question is not appropriate for this forum. I have Windows XP Home Sp2 Here are some register entries: