For complete reinstallation of Icewarp Mail Server, please proceed these steps:

Backup your configuration as MCB file (Admin console menu ~ File ~ Backup configuration)

and backup following folders:

..\Icewarp\mail\
..\Icewarp\Webmail\config
..\Icewarp\Webmail\users

(do not backup whole Icewarp\Webmail folder while it can cause problems when upgrading from older versions)

..\Icewarp\Calendar\
..\Icewarp\Temp\
..\Icewarp\LDAP\ (in case you use it)
..\Icewarp\Spam\ (in case you use Challenge response)

Then stop all services and delete the Icewarp folder. After that, install new version from: http://www.Icewarpmailserver.com/Download/Icewarp.zip

Copy back all backup folders and restore your configuration from the MCB file (use again admin console).

For WebMail Standalone backup following folders:

..\Webmail\config\
..\Webmail\users\
...and folder with mails downloaded to Webmail (if integration is not enabled).

Then delete the Webmail folder and reinstall Webmail standalone. When installation is finished, copy the folders back to their places.