How to upgrade Apache on a Windows server?

Question

I have just upgraded our webserver from PHP 5.3.6 to 5.3.10, and I now want to upgrade Apache as well from 2.2.17 to 2.2.22 (on a Windows Server). How do I go about this in a good way (on a live webserver)? A little downtime is alright, but not too much.

Apache is installed via an MSI installer and I'm not sure how to upgrade safely with the least downtime. Do I just download the latest installer and install that? And what about my config files? I don't think it's possible to have both instances installed 'next to each other'? Or is it?

Solution

For anyone else who searches for this, I found that uninstalling the old Apache (in my case, 2.2.22) from Add/Remove Programs and installing the new version (in my case, 2.2.24) kept all the previous settings.

We had locked down the httpd.conf file and had an application that modified/added files in the "htdocs" directory.

Upon uninstalling and re-installing, all of these files were left unchanged and the new version of Apache Server is reflected.