Unknown User

It's probably a user that was deleted.
-1004

Press Edit and remove the id from the security list.

You might want to check the security tab on root of each partition (C:\ D:\ E:\ ...) to see if the -1004 user is defined in those security settings. It's probably inherited downwards.

Where did you remove the -1004 in the registry?
HKLM\......\Microsoft\WindowsNT\ProfileList?

I'll have to look up the full key if you need it.

Hmmm, why is the advanced button greyed out. Are you not an administrator?

Did the HDD (and files) come from another Windows machine?
Are you dual booting with another version of Windows (e.g. XP)?

That normally happens if the user ID has been assigned by a different Windows installation.
One Windows install doesn't know the names that are assigned to the SIDs by a different Windows install.

This picture shows what W7 says when I look at my XP user folder.

Good point lehnerus2000 - either way, it's an account not currently on the system and it seems as though Oscar53 wants it removed.

Please check the following registry location for the -1004 account
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList

Remove it if found.

You only have the one 500GB drive - how many partitions?
In the Explorer computer view,
right click each drive
pick properties
open the security tab
if -1004 is presented, press the edit button
highlight -1004
press remove
apply to this folder and sub-folders.

let it change the security on the files. It might complain about some system files, but that's ok.

Oscar53 said:

.....
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Group Policy\S-1-5-21-1959337425-3215390515-242915364-1001\GroupMembership
Yes I am the admin and by the way the advanced button was only greyed out on that unknown user.

You're showing a different user: -1001; is that your GUID?

BTW, the title in the image you posted shows Bob Properites
Object C:\Users\Bob
That's what the dialog window has in focus. The advanced tab is for Bob: user -1004 is simply included in the security setting for that object. Advanced should not be greyed out.

No other OS's, no transfers from other machines, just this stange behaviour. It doesn't show up in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList

I will record exactly what happens and post it. Does this forum support video recordings as attachments.

You cannot directly attach a video, but if you post it on a cloud or Youtube, you can post a link to it.

I'd like to see what your system knows about users. Please post a screen shot of
Control Panel > User Accounts >Manage another account
See: Screenshots and Files - Upload and Post in Seven Forums

I'd also like to see how your disks are partitioned.
Having this information makes it easier to a discuss course of action.
See: Disk Management - Post a Screen Capture Image

Thanks

Thanks,

In Explorer, view Computer
Right click C:\
pick properties
open Security tab
press the advanced button
if user -1004 is displayed
press change permissions
select user -1104
press remove
press OK
answer yes if asked to replace security settings

let it change the files

then for each folder on C:\
do the same
check for user -1004 on the security tab
remove and apply

You'll probably only find if on the Users folder

Then check D:\

I recommended this twice before, if you don't want to do it, that's ok - it's your machine. I won't recommend it again.

Good luck,

Bill
.