If you have dragged files to an incorrect location by accident in the OS X Finder, there are several ways to undo this without having to select and drag them all back.
If the Finder in your user account refuses to open, there are a couple of steps you can take to clear settings files and have it open normally.
Dropbox includes a feature that should fix most permissions-related problems experienced with the cloud storage service.
Scientists at Washington University in St. Louis say it may someday be possible to perform a single test to screen for a wide range of cancer types.
The boot drive's format and partition structure can be checked both in the OS X graphical interface and in the Terminal.
Problems with Mail's index may lead to slowdowns and missing messages, but a quick rebuild can fix this.
Sometimes file access errors in OS X may actually be related to a program's sandboxing rather than being a classic file permissions error.
If ColorSync Utility finds problems with profiles that it cannot fix, you may be able to address them by running the utility in root mode.
Sometimes OS X's Disk Utility may show errors with a drive when it's run from one location, but will describe the drive as perfectly healthy when run from another.
If you find windows for a program collapsed in a heap, there are several approaches to help you sort through them.