Exchange Server Updates: Your Guide to CU, SU, and HU Installs

There is 3 types of updates in Exchange, CU, HU, SU.

The CU stands for Cumulative Update, HU Hotfix Update and SU Security Update

If you have CU 13 installed, you cant install the “Exchange Server 2019 CU14 Nov24SUv2” update, first install the “Exchange Server 2019 CU14 (2024H1)” ISO then install the latest SU or HU.

To find out the installed CU version run the following command in the Exchange Management Shell:

Get-ExchangeServer | Format-List Name,Edition,AdminDisplayVersion

Take the build number and search for it in the MS Website

Install CU Upgrade:

To install the CU Updates, do the following

• Install windows updates
• Restart Server
• Put the Server in Maintenance mode (You can find the command here)
• If the Server has Lets encrypt Certificate, use other one temporarly
• Disable Antivirus and Backup
• Mount the ISO
• Run CMD as administrator and open the install.exe that is in the ISO

After the update

• Restart the Server
• Disable Maintenance mode (Again, command can be found here)
• Change Certificate back to letsencrypt
• Enable Backup software
• Enable Antivirus