These steps are optional

Version 1.9.5 and later store information in system-wide folders and registry locations by default, but still support reading user-specific configuration data. As such it is backwards compatible with 1.9.4 and earlier.

Registry

• Export the key HKEY_CURRENT_USER\Software\letsencrypt-win-simple
• Delete the key
• Open the .reg file with your favorite text editor
• Replace HKEY_CURRENT_USER forHKEY_LOCAL_MACHINE and save it
• Import the .reg file

File system

Move the folder %APPDATA%\letsencrypt-win-simple to %PROGRAMDATA%\letsencrypt-win-simple (make sure the original is deleted).

Scheduled task

Should be changed to run as SYSTEM. Running under a specific user does not seem to work if the task is running without a password specified.

---

'Insufficient system resources exist to complete the requested service'

You need to follow the steps above if you are getting this error message when creating a new renewal. This is because entries under HKEY_CURRENT / HKEY_CURRENT_USER follow a legacy structure has a maximum value size of 512kb while HKEY_LOCAL_MACHINE does not (on modern Windows systems). If you have a lot of scheduled renewals, you can hit that 512kb key limit, and that confusing error message will be displayed.