In Windows 7 command prompt, I´d like to list all files of a folder which name does not start with abc. I have tried:
forfiles /P C:\\myFolder\\
Looking at forfiles /?:
/M searchmask Searches files according to a searchmask. The default searchmask is '*' .
which strongly suggests forfiles doesn't support regular expressions, just normal Cmd/Windows wildcards.
On Windows 7 this can easily be achieved in PowerShell:
dir c:\myFolder | ?{ -not($_.Name -match '^abc') } | select Name
(That performs a case-insensitive regular expression match, which doesn't matter in the case of Windows filenames.)
NB. Assuming you want files not starting ABC, which isn't what your (attempted) regular expression says (any filename starting something that isn't a, b or c).