A friend of mine contacted me recently with a problem that he could not figure out on his own. He discovered that two hidden folders had been created on his USB flash drive. One folder was named .spotlight-V100 while the other was named .trashes. This puzzled him as he was certain that they were not created by him or any program that he used to work with. A quick research on the Internet solved the problem.
The .spotlight-v100 and .trashes folders were created automatically by an Apple Macintosh computer system that the USB flash drive was plugged in before. These two folders are automatically created whenever a USB flash drive is connected to a computer system running an Apple Mac operating system. Spotlight is an indexing process on the Mac that will save the information that are gathered in the .spotlight-v100 directory.
The Spotlight program creates a virtual index of all files and folders to speed up search on Macintosh systems. Among the information it records are sizes, modification dates, types, creation dates and other information related to the files on the USB flash drive.
The .trashes folder on the other hand is simply a trash folder for the specific drive which is also created by Apple Macintosh computer systems. Windows users can simply delete both hidden directories to free up disk space. There is however no need to worry that these two folders have been created by malicious software.
Windows users do not need these files at all, and deleting the trash folder should not have any ill-effects when you connect the drive to Mac systems again. Deleting the spotlight-v100 folder on the other hand may slow down search a bit until everything got re-indexed.