I think you should be safe to delete this, they are normally folders left over from windows updates. If you have the external drive connected when the update is installed, the folder might be created there. They're meant to be deleted once the update is finished but sometimes there not.
As it's not on your main drive and not in the WINDOWS folder, you should be fine to delete. I recommend you create a backup of it somewhere else, for example in your my documents folder or, preferably, another external HDD. Monitor the computer and if there are issues, move it back to the original location. After about a month, you should be fine to permanently delete it.
Can I delete these randomly named folders?