Batch Script that gives unique time stamp to rename bulk files - date

Question

I used this script to rename files in bulk with a unique time stamp in a batch file. The idea is to use the second and millisecond to create a unique number, which is added to the filename. The why? The filenames being used is so similar in the naming convention that it is triggering errors on the import program into the database. What doesn't trigger the error is the uniqueness of the filename, which is why I thought of a second and millisecond stamp to the prefix. Now, the code works as intended, but the stamp is not unique. It is as if the code pulls the value from the system and applies to all of the files in the folder instead of one file at a time.
Assume my file names are like this:
File1.txt
File2.txt
File3.txt
File4.txt
When the script is run, it renames the files like this:
1410File1.txt
1410File2.txt
1410File3.txt
1410File4.txt
I was hoping the script would do it like this:
1410File1.txt
1411File2.txt
1412File3.txt
1413File4.txt
The code I used to help me with this problem:
#echo off
for /f "delims=" %%a in ('wmic OS Get localdatetime ^| find "."') do set dt=%%a
set YYYY=%dt:~0,4%
set MM=%dt:~4,2%
set DD=%dt:~6,2%
set HH=%dt:~8,2%
set Min=%dt:~10,2%
set Sec=%dt:~12,2%
set Mil=%dt:~14,6%
set stamp=%Sec%%Mil%
CHDIR /D "c:\TEST\FILES\"
for %%a in (*.*) do ren "%%a" "%stamp%%%a"
Is there an additional programming code that is needed to ensure each filename is renamed differently? I'm on Windows 10 using a simple .bat file. On any given day, I would end up renaming anywhere from 600 up to 1000 files in one sitting so any help would be greatly appreciated!
Thanks in advance!

Answer 1

You answered your own question:
Now, the code works as intended, but the stamp is not unique. It is as if the code pulls the value from the system and applies to all of the files in the folder instead of one file at a time.
Take a look at your code. You
Compute the timestamp once at the start of the run:
for /f "delims=" %%a in ('wmic OS Get localdatetime ^| find "."') do set dt=%%a
set YYYY=%dt:~0,4%
set MM=%dt:~4,2%
set DD=%dt:~6,2%
set HH=%dt:~8,2%
set Min=%dt:~10,2%
set Sec=%dt:~12,2%
set Mil=%dt:~14,6%
set stamp=%Sec%%Mil%
cd down to the desired directory:
CHDIR /D "c:\TEST\FILES\"
iterate over the files in the directory, adding the same timestamp to each file:
for %%a in (*.*) do ren "%%a" "%stamp%%%a"
You need to recompute the timestamp on every iteration of the final loop.
I would also add a pause of a few milliseconds in the loop to ensure that at least 1 millisecond has elapsed between computations of the timestamp.