https://support.eset.com/kb2177

During installation or uninstallation of ESET Remote Administrator (ERA), you may see the error message "Error while reading registry (SYSTEM\CurrentControlSet\Services\SNMP\Parameters\ExtensionAgents\)". This issue was resolved in version 3.0.115. If you are using a version of ESET Remote Administrator earlier than 3.0.115 and wish to upgrade to the latest version, download and install the two files below.

• ESET Remote Administrator Server 4.0 (32-bit): http://download.eset.com/download/ra/era_server_nt32_enu.msi
   
• ESET Remote Administrator Console 4.0 (32-bit): http://download.eset.com/download/ra/era_console_nt32_enu.msi
  
  

If you are unable to download and install the latest version, follow the steps below to fix the issue: 

1. Click Start → Run and then type regedit in the Open: text field and click OK. (In Microsoft Windows Vista, click Start and type regedit into the Start Search text field.) 
    
2. Navigate to the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SNMP\Parameters\ExtensionAgents.
    
3. Right-click on the empty (Default) value and click Delete.
    
4. Re-run your ERA installation or uninstallation.