Ssl – Migrating security certificate from IIS 6.0 to IIS 7.0

.Net is native in IIS7 rather than being an ISAPI filter. That gets you pipelining and greater configuration control via web.config. Another consequence is that URL permissions applied in web.config apply to all resources and not just ones mapped to the ASPNET ISAPI filter as in IIS6. As a consequence, if you want to use ASPNet MVC, it is much easier in IIS7. You are also able to combine HttpModules with non-.NET technologies like PHP. For example, you can use a .NET URL authorization or Microsoft's URL Rewrite Module with something like PHP and it will work just fine.

You only need to create a temporary website with IIS 6.0. IIS 7.0 allows you to create multiple pending requests at a time.

IIS 7.0 actually has a bug that causes the renew function to generate a CSR with a very large key (much larger than you want). Because of this, it is recommended that you create a new pending request instead of selecting the renew option. Once installed you simply switch the SSL binding on the website and you won't have any downtime. This also allows you to generate a new key every time you renew which increases security.

The certificate provider (CA) doesn't care whether you use the new option or the renew option and you could use either option whether you are staying with the same CA or ordering from a new one.