The command format is incorrect. You have two extraneous spaces, one after rrgn and one after the colon. Also it should be a comma after region number not a period (full stop). e.g. You've written:
"rrgn, 41.1: /41.bin" and it should be:
"rrgn,41,1:/41.bin"

Other things to check:
  • Do you have Ldr.bin and correctly named update.txt (NOT updater.txt) in HWID folder?
  • If there's a file named "last_id.bin" in HWID folder you must remove it. Try placing an empty file named update.log in there (make one with Notepad).
  • Do you have correct naming of HWID folder (use same HWID as that of the Ldr.bin in it)?
  • Do you have correct folder layout? Garmin\Updater\xxxx where XXXX is 4 numerals of HWID, e.g. US/EU firmware version zumo 595 has 2436
  • Try a different microSD card, some don't work in some device even if they work in other Garmins.