server full of hidden files- can't delete or see them

You can use the command prompt and use the command

Change your directory to the vol. If it is not mapped you need to map the vol.

Net use x: \\unc path
X:
del *.trc /A:H /S /q

To upload an attachment to EE, you need to press the Upload Button after choosing the file, else your file is just ignored.

.trc files are either network captures or other trace files, like for MS SQL Server Profiler. Them being located in a folder called "unknown" is very strange. WinDirStat should allow you to switch into the corresponding folder via context menu on a file, so you can locate the real location in Explorer. I would definitely look into that folder for the most recent file date - if there are files currently written to, you need to find out which process uses those. You can delete old ones then, but not the current one most probably.

A good way to get a handle on server files is to run Tree Size (Jam Software). Run it in Administrative mode and it will neatly lay everything out for you. This is what I do.

Once you see the files, you can decide what to delete.

hopefully this screenshot works. what is this file? it says it is system files, this is being generated on our F:\ volume which is not a system directory.

What root folder and tree do these files belong to?

It seems some process has run wild.

I suggest you run a complete virus scan with your own antivirus application followed with a scan by Malwarebytes.

ran malwarebytes- it didnt find anything in that directory

Thanks. Those files are in System Volume Information.

Run Disk Cleanup. When it starts. select Clean Up System Files, when that calculates. select all items for cleanup and OK. It may take a while.

it doesn't allow disk clean up- it doesnt even show them. with windows file browser it doesn't see the directory at all, I have ti use a third party tool to even find them.

You have to add Desktop Experience to the Server

yup I did that. thats the only way Disk Cleanup would show up

So the Disk Cleanup should now run. That is the Microsoft supported way to remove old files

in the screenshot above on the volume that is full of the "system information files" all it shows is the recycle bin.

Disk Cleanup can Cleanup the recycle bin. That is an option.

If not look in System, Profiles . Have you built excessive profiles?

all that it shows on the volume available to clean up is Recycle bin, I'm looking to find out how to delete that almost 800gb of data. disk cleanup doesn't seem to see it, file explorer doesnt seem to see them- only the 3rd party app you suggest.
Under c:\users there are 6 user folders showing, but in control panel, user accounts I only have one user account.

Look in Advance System Settings, Advanced, User Profiles, Settings. You will likely see unused profiles in here. Delete these, close out and then when you can, restart the server.

system volume information contains potentially important information.  Stop trying to delete these files and START figuring out why they are there.  Your backup program?  Quite possibly it's your Volume Shadow Copy settings.

AWESOME! This worked!