I've been having a persistent and annoying problem for the last week. I can't rename, delete, move or copy files in Windows Explorer, and I can't save files using any Office program. I get a file permission error. It started after an upgrade to my antivirus program (Avast!), but disabling the program does not help. I can move or copy a file to an external drive within Explorer, and then copy or move it back to the hard drive. It will not save, rename or delete files, nor create a new folder on my external drives. I cannot install new programs because Windows will not create the directory. I can save perfectly well from other programs, such as Notepad or WordPad, but I cannot save a file as a text file from within Word. Files will download from the Internet. I am running Windows XP, service pack 3 on a tablet PC. What I have tried already: Running a registry cleanup program, because some places suggested it might be a registry problem Doing yet another upgrade to my antivirus software Doing a full scan for viruses. Searching tech forums high and low. Changing file permissions by hand. They simply change back. Checking in Task Manager for any odd programs, but everything seems to be fine there.