One of the problems of working in a cloud-based environment, particularly if you don’t use Team Drives is that users can accidentally remove/delete files that others may need to use. Luckily, there are a couple of options you have available.
If the user knows they deleted a file, then they can navigate to their Drive Trash, locate the file and click restore to recover the file.
If the user has emptied their trash, then the administrator can follow this tutorial to recover Drive files within a specified time period. Note that there is a 30 day grace period for this to occur within, otherwise, it’s all bad news!
Of course, this doesn’t help if the user is unaware of whether they deleted a file or not! In this situation, you may need to do more in-depth recovery by a specialist.
If this is occurring, we strongly suggest you look at moving your organisation’s critical files into Team Drives.