S-1-5-21-x-x-x-1006 is in my internal 2nd HDD

when I tried to install Windows Media Player 11 on my Dell desktop running Win XP Pro SP3, I received 3 warnings from Zone Alarm Pro stating it had blocked 3 viruses, but would not display the virus names.

I ran one video file using Windows Media Player 11, it ran fine.
But then I decided to uninstall Player 11.
I used Unlocker Assist to unlock the remaining Player 11 folders & delete them in the Recycle Bin.
My Pc gave me a warning to insert a Win XP Pro CD with SP3.
I loaded my Dell OS CD, but my PC refused it.
I had successfully deleted all Player 11 folders from my PC & rebooted.
It ran fine.

I then tried surfing on the web using Firefox.
When I closed Firefox, I noticed that one of my files was on my desktop labelled (~$ )
I checked my 2nd HDD (attached internally) & looked for my file & it matched.

I then tried the following:
I right-clicked on the file & clicked the Properties option,
clicked the Security tab,
clicked the Advanced button

I spotted
S-1-5-21-2976122918-2254641369-676893803-1006 with a red ? next to the user profile plus it had the same permissions as Administrator & SYSTEM
Full Control, Modify, Read & Execute, Read, and Write.

I then remove the checkmark by clearing
Inherit from parent the permission entries that apply to child objects.

I then clicked the Copy button

I made sure that S-1-5-21-... was highlighted

I then clicked the remove button

I then clicked the Owner tab

I again spotted
S-1-5-21-... with a red ? next to the user profile

I highlighted my name, clicked Apply & saw my name as Owner & clicked OK twice

I checked all my other files & folders in my 2nd HDD & noticed that
S-1-5-21-... was on most of my files and folders, some of the files & folders had S-1-5-21 under the Security tab and some of the other files and folders had S-1-5-21 under the Owner tab.

I also noticed, that there was some open Group and User Permission windows on my desktop. I just closed them or clicked OK.

I made sure that I shut down my PC and rebooted to take effect.

I went through all of my files & folders in my 2nd HDD to delete S-1-5-21
it took 2 days.

I ran Malwarebytes' Anti-malware & it captured/deleted 3 trojan.dropper that was in my C:\ under System Vol Info\restore registries

I decided to recheck my files and folders in the 2nd HDD, but I spotted S-1-5-21 again in some files and folders that I had deleted it before.

I also noticed again that there were some open Group and User Permission windows on my desktop & again I either closed them or clicked OK.

I know that some hacker(s) wanted to create S-1-5-21 as shared admin & wanted to transfer/move all of my files and folders from my 2nd HDD without my permission & without being seen by me.

I am very tired of going through all of my files and folders in my 2nd HDD just to get rid of S-1-5-21, but it keeps mysteriously reappearing!

I think this is some sort of hidden script that was somehow installed in my 2nd HDD.
I also think this script was created on a domain/server & probably used my e-mail to find my PC on the network.

My question is S-1-5-21-2976122918-2254641369-676893803-1006 a
C:\Recycler\S-1-5-21-x-x-x-1006\.exe virus?

If so, how can I find it & how do I delete it without messing up my 2nd HDD?

I request complete step-by-step instructions of what to do.

I do NOT want to go to any PC repair shop & waist my time & waist my money, besides I have no money!

:cry(