I was able to figure something out. By the way, I used MKVToolNix GUI to remove tags for MKV files, correction on previous comment/posting. As for the mp4 files, it was odd. I downloaded something called "File Property Edit" it is free actually. It said it would allow you to edit all property fields, even those that normally you couldn't edit. I couldn't figure out how to edit fields, playing through the menu and options of this application, once I imported an mp4 into the application. It had a bunch of settings but nothing said what the settings were for, it would just give a bunch of "Yes" or "No" options, without really any description as to what they did.
I ended up finding a setting under the "File attributes" called "Read-only", which I set that to "No", and then applied changes. OK, so before someone makes a comment as to why I didn't just change the attributes under the properties of the file itself, so Read-only was unchecked, yes I already made sure this was unchecked. I also made sure the folder this file was in also wasn't read-only. All settings were correct and it should have allowed me to change the properties of this file, but I couldn't. Yes, I am also admin and not a standard user.
Anyway, after making the change to this file with this application I was then able to change the file's tags, like the Title under details by going into "Remove Properties and Personal Information". The odd thing is, it allowed me to change all the files within the folder after making the adjustment to the one file. I selected all of the files and removed the properties for all of them. The only ones this didn't work for was the MKV files, which then I just used the MKVTool that I previously mentioned. So this worked for me and my issue is resolved.
Now for the next task, I want to figure out how to add a picture to each video. Some of them have it and others don't. There must be an application that allows for that. I am not sure and don't think this will be possible for MKV files though. I did download something and it shows a screen caption of all the videos (including MKV) that doesn't already have a picture, it forwards however far into the video (minutes & seconds) that you specify and applies that frame, but it does that same specified time for all videos on the computer and not just certain ones that you select. This isn't what I want, but would like to apply a poster somehow. I read that using the MKVToolNix application you can attach a poster/picture to the video. I tried that and it does allow you to attach a picture, but not sure what the point is as it doesn't show up anywhere in the file after you MUX it. If you import the video back into MKVToolNix, you can see the file is still attached, but it doesn't show up as the file's icon or poster like I would expect. If someone has ideas on attaching posters to files please post them. I hope the information I supplied will help someone.