Hi Ariel,
So you have a couple of options, one would be to upgrade your existing app (Let’s Encrypt Win Simple is now called win-acme GitHub - win-acme/win-acme: A simple ACME client for Windows (for use with Let's Encrypt et al.)), you would need to refer to their support forum for help with that.
We do also have some basic support for monitoring renewals from other certificate managers (some versions of win-acme, posh-acme etc), but we don’t offer any migration at this time.
Alternatively, you could move to Certify The Web. We don’t offer a migration tool so you’d need to setup new managed certificates in Certify The Web. Note that you can use both tools at the same time as long as it’s for different websites (you don’t want them competing to renew the same certificates). Unlike win-acme, Certify is a commercial tool with a support helpdesk ticketing system so although there is a free Community Edition it is limited to managing a small number of certificates before you need to upgrade.
To try out Certify The Web, setup a managed certificate for one of your sites and see how you feel about moving to the app, if it’s right for you then setup all of your managed certificates and disable your old letsencrypt-win-simple scheduled task. I’d recommend experimenting on a test system if you can so you can try out all the options without affecting your production system.
Certify works as a background service, so it doesn’t have any scheduled tasks to maintain.