Renaming files overwrites part of the filename

I ahve a directory full of files, and I want to rename each of them to have TA_ in front of the original file name. file1.txt should be renamed to TA_file1.txt. What I am getting is TA_e1.txt instead.

ren "c:*.txt" "TA_*.txt" is the command I am trying to use.

The file names are all of various lengths, and no matter what I try, it always overwrites the first 3 characte开发者_如何转开发rs of my file name....

A simple one liner would be:

for %i IN (*.txt) DO ren "%i" "TA_%i"

This loops over all files (*.txt) and passes their name in the %i variable to the ren command. ren can then use the %i content to expand it with your desired prefix.

The command will only work for files in the current directory. For more complex things you should write a batch file. Come back if you need help with that.