Hi I do a file/folder backup every Sat. morning. I now have my original full file/folder backup and several differential backups. Can I remove any of those or do I need them all if I ever have a reason to use them.
Each differential backup is independent of all other differential backups. You DO need the full backup that the differential refers to.
Having said that, when you restore using a specific differential you are restoring the files to the date/time that the differential was created. So if you delete a differential you cannot get any files that existed ONLY at that time. So if you created a file the day before a differential was made and deleted the file the day after that differential was made, then you deleted THAT differential you would not be able to get that file back.
So, generally it is fine to delete older differentials to make more space on the drive where your backups are saved.