--- title: "Custom Script" description: "If you have customized your own script to be used when running a recovery plan, you can override the following parameters for the Custom Script step: To allow the script to run inside the guest OS of a processed machine, it is required that you..." canonical: "https://helpcenter.veeam.com/docs/vro/userguide/custom_script.html" breadcrumb: "User Guide > Appendices > Appendix A. Recovery Plan Steps > Steps Available > Custom Script" dateModified: "2026-08-26" --- # Custom Script If you have [customized your own script](uploading_scripts.md) to be used when running a recovery plan, you can override the following parameters for the **Custom Script** step: ::: important To allow the script to run inside the guest OS of a processed machine, it is required that you have Microsoft PowerShell 3.0 and .Net Framework 4.0 installed on each machine for which you enable this step. :::

Parameter	Description	Default Value
Critical Step	Defines whether the step is critical for machine recovery. If you mark the step as Critical, its failure for a machine from a critical inventory group will halt the plan.	No
Run Step During a DataLab Test	Defines whether the step will be executed during plan testing in a DataLab.	Yes
Run Step During Undo and Failback	Defines whether the step will be executed during the Failback and Undo Failover operations.	Yes
Timeout	Maximum amount of time (in seconds) for the step to execute.	600
Retries	Number of retries that will be attempted if the step fails on the first try.	3
Script Execution Location	Defines whether the script will run on the Veeam Backup & Replication server, on the Orchestrator server or on the in-guest OS. Note: The script cannot be executed on the in-guest OS when restoring VMs to a Microsoft Hyper-V environment.	Veeam backup server
Windows Credentials	Credentials required to gain access to the in-guest OS. Applies only if the Script Execution Location parameter value is set to In-Guest OS.	—