Veeam Backup Error: 'Failed to prepare guest for hot backup'

KB ID 0000799

Problem

While backing up a couple of servers (SBS box and a TS/RDP Server) I got this error;

Failed to prepare guest for hot backup. Error VSSControl Failed to prepare guest for freeze, wait timeout 900 sec

This is common if the target server is a ‘busy’ server (like SBS or SQL). You may need to make a registry change on the Veeam Server.

1. Start > Run >regedit {enter}.

2. Navigate to;

HKEY_LOCAL_MACHINE > SOFTWARE > VeeaM > Veeam Backup and Replication

3. Create a new 32 bit DWORD value called VssPreparationTimeout and set its value to 180000 decimal (30 minutes).

3. Then restart the Veeam services, and try again.