For IDM version 6.21 and higher
Important - use registration only from this patch so how it depending regdata. Not use another keys, keygens, patches, etc. for registration if use this patch.
When first using recommended  in early apply 'Cleanup', also this can be used to clean the traces of this patch if migrating to another medicine.
Patch options:
remove sign - removal the digital signature from IDMan.exe
disable update - additional crack to removal IDM's updates check
Register options:
remove oldreg - clear curve (some patches create unnecessary registry keys, depending on the OS architecture) registration

upd. added two more simple variants:

nokill - process IDMan.exe will not be forcibly terminated and restarted, if the patch applies to
%ProgramFiles[(x86)]%\Internet Download Manager\IDMan.exe if this running, instead, will be a warning message.

simple - check for running IDMan.exe totally removed.

upd2.
new_disable_update_method - for IDM version 6.25 and higher - unlike previous patches - update turned off,
but will be available for updates manually in the program interface.