It is common for us to delete some unwanted files in order to free up disk space, since the system runs so slowly and your patience is about to run out. In fact, the items removed from the Windows computer are not really gone. They are saved in the recycle bin in their original state. So you still have a chance to recover the files unless you empty the Recycle Bin which will result in the data loss. Of course, you can use the Recycle Bin to store files which seem to be useless at this stage. However, the space is limited that once it is over the size of rated space, the content would be automatically deleted to release the space for the new one. This is the reason why your files are missing, since you never perform any operation of emptying the recycle bin.