Believe it or not gravity is not really a force, it is an acceleration and on Earth it is about 32 feet/sec2. This same science principle applies in decelerating devices like parachutes and parafoils. The parachute decelerates or slows down the fall of the object.
What is a .DS_Store or ._ AppleDouble file? .DS_Store files are created by OS X to store metadata about folders and files including viewing options, icon positions and color labels. ._ AppleDouble files are created by the OS X when an application adds resource data or metadata to a file on a disk whose format doesn't support resources or metadata.
The %SYSTEMDRIVE%\Windows\Installer folder is a cache for installation files and patches (MSP files) and removing those will cause you to not being able to repair or uninstall applications, and in some cases not removing patches or applying new patches to software.ne of them being the %SYSTEMDRIVE%\Windows\Installer folder. You cannot under any circumstances delete files from this folder manually as this not only may but most likely will break software that is installed using MSI files, or Windows Installer files.